When a celebrity dies in unusual circumstances it's usually not long before the inevitable conspiracy theories begin to surface.
But over the years there have been more than a few deaths that have rocked showbiz land and raised many a sceptic's eyebrow.
From Jeff Buckley drowning, Marilyn Monroe's suicide, the drive-by shootings of Tupac and the Notorious B.I.G. and Heath Ledger's drug overdose, many are still questioning the exact cause of death of some of the world's most famous faces - years after they died.
Mysterious Celebrity Deaths
Jeff Buckley(01 of25)
Only 31 and with a devoted cult following, Jeff Buckley produced only one recorded studio album but made a huge impact as a musician and artist. His band's album, "Grace," was released in 1994 and included a stunning cover of Leonard Cohen's "Hallelujah," which Rolling Stone deemed one of "The 500 Greatest Songs Of All Time." In May 29, 1997, Buckley -- a fixture in downtown New York's music scene -- was in Memphis, where he went swimming in the Wolf River Harbor, and disappeared. According to reports, he was familiar with the river, fully clothed, and in good spirits when entering the river, though he did not return. On June 4th, his body was spotted and his death subsequently ruled an accident. A statement from the Buckley estate officially claiming it was "not 'mysterious,' related to drugs, alcohol or suicide. We have a police report, a medical examiner's report, and an eye witness to prove that it was an accidental drowning." (credit:Michel Linssen, Redferns / Getty Images)
Michael Hutchence(02 of25)
On Nov. 22, 1997, Australian musician and actor Michael Hutchence was discovered dead in Room 524 of Double Bay, Sydney's Ritz-Carlton hotel. A coroner who found alcohol and drugs later determined the incident to be death by suicide, but years later, his girlfriend Paula Yates claimed the star's death was possibly an accidental suffocation brought on by autoerotic asphyxiation. (credit:Keystone / AP)
Anna Nicole Smith(03 of25)
Anna Nicole Smith, the rags-to-riches Playboy Playmate, was 26 years old when she married 89-year-old wheelchair-bound oil tycoon J. Howard Marshall. For years, she was a tabloid sensation and a realty TV star. After Marshall's death, a lengthy court battle over Marshall's inheritance proved more lurid, draining and outlandish than any Hollywood script, eventually reaching the Supreme Court in September 2010 -- not that Smith would live to see its outcome.On Sept. 7, 2006, while on vacation in the Bahamas, Smith gave birth to her daughter Dannielynn. Three days later, Smith's 20-year-old son Daniel Smith died in the same hospital, allegedly from a prescription drug overdose. Soon after, a distraught Smith married long-time friend and lawyer (and listed father on daughter Dannielynn's birth certificate) Howard K. Stern. Five months later, Smith was found dead in a Hard Rock Hotel and Casino in Florida from a lethal "combined drug intoxication." (credit:WireImage / Getty Images)
Brittany Murphy(04 of25)
Most knew her as Alicia Silverstone's chirpy, scene-stealing sidekick in "Clueless," but Brittany Murphy stood at the brink of a promising Hollywood career that included a plum role in the Eminem film "8 Mile" and a public romance with her "Just Married" co-star Ashton Kutcher. But things spun out of control for Murphy, who was appearing increasingly more frail in her later years. On Dec. 20, 2009, the Los Angeles Fire Department arrived at Murphy's home to find the 32-year-old actress unconscious. Murphy was pronounced dead on arrival at the Cedars-Sinai Medicinal Center after going into cardiac arrest. Though the primary cause of death was declared as pneumonia, many speculated that over-the-counter and prescription medications were to blame. Husband Simon Monjack died just five months later, also from pneumonia. (credit:Peter Kramer, Getty Images)
Heath Ledger(05 of25)
Heath Ledger, 28, passed away on a chilly January afternoon in 2008, having just completed filming the role of a lifetime -- his brilliant turn as The Joker in Christopher Nolan's "The Dark Knight" -- vaulting his career to new heights.Just two years after his Oscar-nominated performance in "Brokeback Mountain," Ledger's body was found naked and not breathing by his masseuse. His death was deemed accidental by the Chief Medical Examiner of New York. They wrote in a statement: "We have concluded that the manner of his death is accident, resulting from the abuse of prescription medications." (credit:Albert Pizolli, AFP / Getty Images)
Kirsty MacColl(06 of25)
English musician Kirsty MacColl, well-known for writing hits in the 1980s like "They Don't Know" for Tracy Ullman, died at age 41 in a Mexican boating accident on Dec. 18, 2000. While diving at a reef near Cozumel, a speedboat zipped through waters towards her sons. In an effort to save them, MacColl was hit by the boat and nearly cut in half by the propeller. The boat that killed her was owned by Mexican supermarket mogul Guillermo González Nova, who was on board with family and a crew member José Cen Yam. Cen Yam claimed he piloted the boat, leading to a conviction and small fine. But MacColl's boyfriend said Nove was at the helm and critics believe Cen Yam took the fall for the wealthy patriarch. (credit:Redferns / Getty Images)
Michael Jackson(07 of25)
The presence of multiple anti-anxiety medications and the general anesthetic Propofol in Jackson's system prompted a murder investigation into the pop icon's June 25, 2009 death. While some say that Jackson was heavily addicted to the pain medicines, a court convicted Jackson's personal physician, Conrad Murray, of involuntary manslaughter on Nov. 7, 2011, for administering the lethal dose. (credit:Peter Still, Redferns / Getty Images)
Mysterious Hollywood Deaths -- Natalie Wood(08 of25)
Thirty years following her death, the Los Angeles County Sheriff's Department reopened the Natalie Wood case on Nov. 17, 2011, claiming officials received credible new information. The original investigation concluded that Wood, 43, accidentally drowned while yachting off the coast of California with husband Robert Wagner and their guest Christopher Walken. But the boat's captain Dennis Davern claims he heard the Oscar-nominated actress fighting on the deck with Wagner. Shortly thereafter, no one could locate Wood. Davern claims Wagner impeded their search for Wood by refusing to turn on lights or call for help. Wood's body was found the morning of Nov. 29, 1981 on Santa Catalina island, about a mile from the yacht. (credit:Ernst Haas, Getty Images)
Notorious B.I.G.(09 of25)
Immortalized by friend P. Diddy's 2009 biopic, "Notorious," Biggie Smalls, née Christopher George Latore Wallace, dominated a rapidly growing hip-hop scene in the early '90s and blew through the roof with hits like "Juicy" and "Big Poppa." He also found himself at the center of an increasingly tense bi-coastal rivalry that pitted Tupac Shakur on the West Coast against Wallace, Sean Combs (later P. Diddy) and Uptown Records' founder Andrew Harrel on the East Coast. Wallace was shot in the chest four times early in the morning on March 9,1997, when a black Chevrolet Impala SS pulled up to Wallace's car in Los Angeles and its driver shot through the window. Wallace was pronounced dead a short while later at the Cedars-Sinai Medical Center; many consider his death an act of revenge for the mysterious killing of Shakur in 1996 . Wallace's murder case remains unsolved. (credit:Ron Galella, Ltd. / WireImage / Getty Images)
Roscoe 'Fatty' Arbuckle(10 of25)
Silent film star Roscoe "Fatty" Arbuckle became one of the most famous men in America throughout the 1910s, starring in 37 films with everyone from Charlie Chaplin to Harold Lloyd and Buster Keaton. (He is credited with discovering Lloyd and Bob Hope, while also mentoring Chaplin.)In 1921, Arbuckle signed a then-record deal with Paramount worth $1 million. To celebrate, he threw a party over Labor Day at the St. Francis Hotel in San Francisco. An actress named Virgina Rappe became ill at the party; she died four days later, and Arbuckle was accused of raping and accidentally killing her. Following three trials, Arbuckle was finally cleared of Rappe's death, but by then the damage had been done: his films were banned for short period of time, and he couldn't get work even after the ban lifted. Arbuckle returned in 1932 and later signed a contract with Warner Bros. to appear in feature-length comedies. "This is the best day of my life," he was quoted as saying. Arbuckle died that night in his sleep after suffering a heart attack; he was 46.As for Rappe, she died from a ruptured bladder, which may have been caused from a botched abortion she had days before the Labor Day party. (credit:Hulton Archive / Getty Images)
Bruce Lee(11 of25)
On July 20, 1973, martial arts star Bruce Lee, 32, died as the result of an apparent allergic reaction to Equagesic, a painkiller. According to the coroner's report, Lee died "by misadventure."He did suffer from seizures -- one happening just a month before his death -- but popular urban legends persist that Lee was murdered by triads, a curse on his family and/or the delayed reaction from Dim Mak strike (called the "Touch of Death"). (credit:Archive Photos / Getty Images)
Thomas H. Ince(12 of25)
Known as "The Father of the Western," Thomas Ince was a famed silent film actor, producer, writer and director in the 1910s and early 1920s. On Nov. 15, 1924, on the yacht of William Randolph Hearst, Ince fell ill and was returned to shore. He succumbed to heart failure, on Nov. 19, but in the newspaper that evening it was reported that Ince was shot on Hearst's yacht.So, what possibly happened? In one version of events, Hearst allegedly walked in on Marion Davies -- whom he was in love with -- and Charlie Chaplin in a compromising position. During the ensuing struggle, Ince arrived and was accidentally shot. Another theory posits that Hearst shot Ince thinking he was Chaplin. The Peter Bogdanovich-directed film 'The Cat's Meow' with Kirsten Dunst focused on Ince's mysterious death. (credit:Hulton Archive / Getty Images)
Marilyn Monroe(13 of25)
On Aug. 5, 1962, 36-year-old Marilyn Monroe was found dead in her home, after overdosing on barbiturates. The coroner's report listed Monroe's death as probable suicide, but many -- including the first LAPD officer to the scene -- believe she was murdered.But skeptics say there was no trace of drugs in Monroe's stomach, meaning she didn't swallow the drugs. They also say she was covered in bruises, including a major one on her hip. The toxicologist on the case wanted to examine her to understand how the drugs got into her system, but the initial examination destroyed organs.Another suspicious sign was revealed that Monroe had enough chemicals in her system to kill 10 people, but intravenous injection was ruled out by examiners.At the time of her death, Monroe was allegedly involved in a relationship with John F. Kennedy, and perhaps his brother, Robert. FBI files released in 2006 showed that Monroe was considered a security risk after cavorting with known communists during a vacation in Mexico. (credit:Michael Ochs Archives / Getty Images)
George Reeves(14 of25)
In 1951, George Reeves became Superman on television. It was the biggest role of his career, and the one that sank it as well: Reeves could never escape the shadow of playing Superman -- he was reportedly cut out of 'From Here to Eternity' after test audiences shouted, "There's Superman!" at the screen -- and, on June 16, 1959, killed himself because of depression over his career.Or maybe he didn't. While the official cause of death is suicide -- Reeves was found laying naked on his bed, face up, with a gun between his feet on the floor -- many believe he was the victim of an accidental shooting or murder. It was rumored that George's former girlfriend, Toni Mannix, ordered a hit on him after he broke up with her. Mannix died from Alzheimer's disease in 1983, but in 1999, Los Angeles publicist Edward Lozzi said that Mannix confessed to him that she told a priest she was responsible for Reeves's murder.In 2006, a film about Reeves life and death called 'Hollywoodland' was released. Ben Affleck played the doomed Superman (credit:Hulton Archive / Getty Images)
Thelma Todd(15 of25)
Between 1926 and 1935, Thelma Todd appeared in over 120 films, including the Marx Brothers' 'Horse Feathers' and 'Monkey Business.' On Dec. 16, 1935, Todd was found dead in the garage of actress Jewel Carmen, the former wife of Todd's lover and business partner. The cause of death was carbon monoxide poisoning.Police found that Todd had spent the night before her death at a popular Hollywood restaurant, where she had an argument with her ex-husband; she then retreated to Carmen's home, which was a block away from a restaurant that she owned.Whether foul play was involved in the death remains up for debate. Some believe Todd was targeted for extortion, while others wonder if she was locked inside the garage by a murderer. Blood was found on her head and dress, leading some to believe she was knocked unconscious before being exposed to the gas. Complicating matters? Todd's ex-husband was murdered two years later. (credit:Hulton Archive / Getty Images)
Bob Crane(16 of25)
The 'Hogan's Hero' star was murdered on June 29, 1978, allegedly bludgeoned to death with what might have been a camera tripod. Crane had a voracious sexual appetite and often filmed his escapades with the help of a man named John Henry Carpenter, who police suspected in Crane's death.No charges were filed against Carpenter until 1990, but Carpenter was acquitted because of a lack of evidence. The murder remains unsolved, but authorities believe Carpenter was the killer. He died in 1998. (credit:Hulton Archive / Getty Images)
Tupac Shakur(17 of25)
Rapper and actor Tupac Shakur was killed on Sept. 9, 1996 in Las Vegas after attending the Mike Tyson vs. Bruce Seldon boxing match. Video surveillance from the MGM Grand showed Shakur and his entourage fighting with an alleged Crips gang member. Later, as a passenger en route to a Vegas club, Shakur was killed by a shooter in a car that pulled alongside him. No one has been charged in Shakur's death, but theories contend it had to do possibly with the fight earlier that night or a long-simmering feud with East Coast rapper Notorious B.I.G. (credit:Steve Eichner, Getty Images)
Bobby Fuller(18 of25)
On July 18, 1966, Bobby Fuller, who sang "I Fought The Law," was found dead in a car parked outside his Hollywood home. An autopsy report stated that Fuller's face, chest, and side were covered in hemorrhages likely caused by gasoline vapors and heat. The coroner checked "accident" and "suicide" as causes of death. Those checks, however, were accompanied by question marks, leading some to believe that Fuller was actually murdered. (credit:Michael Ochs Archives / Getty Images)
Lana Clarkson (19 of25)
B-movie actress Lana Clarkson was killed by Phil Spector in the music producer's California mansion on Feb. 3, 2003. They had met in the House of Blues earlier that night and Clarkson was killed by a gunshot to the face. Spector denied the murder charges, claiming her death was accidental and that she had "kissed the gun." A judge declared a mistrial when a jury couldn't reach a verdict, but another jury found Spector guilty of second-degree murder in 2009. He was sentenced to 19 years in prison. (credit:Albert L. Ortega, WireImage / Getty Images)
David Carradine(20 of25)
On June 4, 2009, David Carradine was found dead in a hotel room in central Bangkok, Thailand, where he was shooting his latest film "Stretch." Speculation pointed to death by suicide, given that police found Carradine naked and hanging by a rope in the room's closet. However, two autopsies later claimed that the death was not a suicide, leading many to accept the theory that Carradine died from accidental suffocation during autoerotic asphyxiation, a pleasure that his ex-wives claimed he enjoyed. (credit: Robert Mora, Getty Images)
Grace Kelly(21 of25)
Grace Kelly was an American movie star who married Monaco's Prince Rainier III in 1956, raising her profile as she became a royal. She died in 1982 while driving with her daughter in France, apparently suffering a stroke while in the driver seat on a mountainous road. Her daughter survived, but suffered serious injuries. (credit:FPG / Archive Photos / Getty Images)
Brandon Lee(22 of25)
On March 31, 1993, Brandon Lee died after being shot by actor Michael Massee on the set of his latest film, "The Crow." The fatal wound, which struck Lee's abdomen, was fired from a gun that was hastily rigged with improperly constructed dummy rounds and used without approval from the film's hired weapons coordinator, who had been dismissed early that night. The death was ruled accidental and no charges were filed. (credit:WireImage / Getty Images)
Corey Haim(23 of25)
Eighties teen heartthrob Corey Haim passed away unexpectedly at the age of 39 in the spring of 2010. The actor -- whose Hollywood career as a youngster included roles in films like "Lost Boys" and "License to Drive" -- had publicly struggled with prescription drug abuse and made news when he claimed he had been sexually abused at age 14 by an acquaintance of his then-best friend Corey Feldman. Haim got attention again in 2008 when he ran an advertisement in VARIETY stating he was ready to work and was serious about a comeback. But Haim became destitute and increasingly troubled. In March 2010, his mother called the police in a frantic message that leaked online: "Oh my God. I think my son is dead" before administering CPR. Haim's death was later said to be due to pneumonia and a lethal cocktail of prescription drugs. (credit:WireImage / Getty Images)
Andy Kaufman(24 of25)
In 1984, the comedy world lost one of it's finest entertainers -- or at least they think they did. Known for his elaborate stunts and ability to toy with an audience's emotions, Andy Kaufman and his death were surrounded by mystery as the 35-year-old star passed away from an undisclosed illness. Kaufman claimed that if he were to fake his own death, he would return 20 years later, which would have been in 2004. (credit:Ron Galella, WireImage / Getty Images)
Johnny Stompanato(25 of25)
On April 4, 1958, underworld bodyguard Johnny Stompanato was stabbed to death outside the Beverly Hills home of his girlfriend actress Lana Turner. While Cheryl Craine, Turner's then teenage daughter, claimed that she stabbed "Handsome Harry" while defending her mother, skeptics have argued that it was in fact Turner who killed Stompanato, only to place the blame on her daughter who she knew would face minimal consequences. (credit:AP)