UPDATE:

A naked man was shot dead by Miami police as he chewed at the face of another naked man.

The circumstances of the horrific attack are still unknown – and the victim remains in hospital with grave injuries.

The gruesome drama unfolded on Saturday off the city's MacArthur Causeway, with the aftermath captured on film by a Miami Herald surveillance camera.

Witness Larry Vega told WSVN-Fox 7 he saw a man biting the victim’s face.

He said: “I told him to get off and the other guy just kept eating the other guy away.”

The cyclist notified police, who ordered the man to stop.

Vega added: “The guy just stood, his head up like that, with pieces of flesh in his mouth. And he growled.”

The officer fired, but the man continued to chew, prompting him to continue shooting, eventually killing him.

Police say the attacker may have been suffering from a drug-induced mania which causes the body to heat up, causing some users to strip off, the Miami Herald reported.

Armando Aguilar of the Miami Fraternal Order of Police suggested the drug may have been a new form of LSD.

He told NBC 6: "Seventy-five to 80 percent of his face was missing, and he was actually swallowing pieces of the man's face."

The identity of either man has not yet been released.

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  • The first police officers on the scene rush towards Rudy Eugene and Ronald Poppo following the attack on Miami's MacArthur Causeway on May 26

  • A pair of naked legs can be seen in the images, which were captured by the Miami Herald's surveillance camera

  • Officers approach the two men

  • It is unknown if Rudy Eugene had been shot dead at this point

  • An officer vaults over the wall as he races towards the bloody scene

  • Crowds gather at the horrific scene

  • A City of Miami police officer stands watch near the scene

  • This is believed to be one of the first pictures taken after Rudy Eugene was shot dead by police. A seriously injured Ronald Poppo lies beside him

  • An undated mugshot of Rudy Eugene

  • An undated mugshot of Ronald Poppo

  • A pixellated image of Ronald Poppo's injuries upon his arrival to Miami's Jackson Memorial Hospital

  • Conscious and speaking, Ronald Poppo allowed this photo of himself to be released by the hospital

  • Ronald Poppo holds onto the hands of two Jackson Memorial Hospital staff

  • Gloria Allred, Yovonka Bryant

    Yovanka Bryant,left, and her lawyer, Gloria Allred, discuss a recent attack on a homeless man by Brant's boyfriend Rudy Eugene, during a news conference, Wednesday, June 6, 2012 in Miami. Bryant said she last heard from Eugene, the day before he chewed off the face of a homeless man alongside a Miami highway. A police officer shot and killed Eugene. The homeless man remains hospitalized. (AP Photo/J Pat Carter)

  • Gloria Allred, Yovonka Bryant

    Yovanka Bryant, right, and her lawyer, Gloria Allred, show a photo of Bryant and her boyfriend Rudy Eugene, during a news conference, Wednesday, June 6, 2012 in Miami. Bryant said she last heard from Eugene the day before he chewed off the face of a homeless man alongside a Miami highway. A police officer shot and killed Eugene. The homeless man remains hospitalized. (AP Photo/J Pat Carter)

  • Former 'bath salts' addict Freddy Sharp told CNN about his experience of the drug Rudy Eugene is believed to have been under the influence off when he attacked Ronald Poppo

  • Westbound traffic on the MacArthur Causeway, approaching the Northeast 13th Street ramp in Miami, is backed up Saturday May 26, 2012, after a police officer fatally shot a naked man on the ramp who was chewing on the face of another naked man. The victim remained hospitalized Monday. (AP Photo/The Miami Herald, Marsha Halper) MAGS OUT

  • A Google Maps image of where the attack occurred