Simon with Simone Battle during her audition round on the US 'X Factor' in 2011
Simon took to Twitter to reflect on the tragedy of the contestant he mentored on the US version of the show in 2011.
"I am so sad to hear about the news Simone Battle has passed away. She was such a fun nice person. It's such a loss. Rest in peace Simone."
Cheryl Fernandez-Versini, who has returned to the show this year, and who also met Simone during her stint on the US show, shared her own sadness, saying, "Such tragically sad news to hear of the passing of Simone battle.. My thoughts and prayers are with her loved ones #RIPSimone
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Simone Battle
A joint statement from Reign Deer Entertainment, Robin Antin, Kemosabe Records, and RCA Records confirming the sad news was then released on Saturday afternoon, which said: “We are deeply saddened by the tragic news of the loss of Simone Battle of G.R.L.
“Simone was an exceptional young talent and human being, and we are all devastated to learn of her passing. Our thoughts and prayers are with her family and loved ones at this time.”
Simone first became famous after making it through to the live shows of the first series of ‘The X Factor’ in America in 2011, where she was mentored by Simon Cowell.
She later received praise for her ‘Clueless’-inspired solo music video, ‘He Likes Boys’, which she posted online following her elimination from the competition.
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Simone with the other members of G.R.L.
A year later, she was chosen by the original founder of the Pussycat Dolls, Robin Antin, to join her new five-piece girl group G.R.L., alongside Lauren Bennett, Emmalyn Estrada, Natasha Slayton and Paula van Oppen.
The band released their first major release, ‘Ugly Heart’, in the UK last Sunday.
Simone's father Anthony described his daughter to MailOnline as "an exuberant person and a very loved person. She will be greatly missed and loved".
The death of the young singer is still being investigated, although TMZ report that law enforcement officers have indicated it was suicide.
RIP: Celebrities We've Lost In 2014
Lynda Bellingham(01 of27)
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After a lengthy battle with cancer, the actress and 'Loose Women' panelist died at the age of 66 in October. (credit:Stuart C. Wilson via Getty Images)
Robin Williams(02 of27)
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Comedy legend Robin Williams took his own life in August 2014. (credit:Vera Anderson via Getty Images)
Joan Rivers(03 of27)
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Controversial comic Joan Rivers died in hospital at the age of 81 in September. (credit:Bravo via Getty Images)
Rik Mayall(04 of27)
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The actor and comedian Rik Mayall died at the age of 56 in June. (credit:Getty Images)
Roger Lloyd Pack(05 of27)
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Actor Roger Lloyd Pack died on 15 January 2014 at the age 69 following a battle with pancreatic cancer. (credit:PA)
Kate O'Mara(06 of27)
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'Dynasty' star Kate O'Mara died at the age of 74 on 30 March 2014. (credit:PA)
Peaches Geldof(07 of27)
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Peaches Geldof was found dead at her Kent home on 7 April 2014. (credit:PA)
L'Wren Scott(08 of27)
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L'Wren Scott, fashion designer and Rolling Stones frontman Mick Jagger's longtime girlfriend, was found dead in NYC on 17 March 2014 of an apparent suicide. (credit:Getty)
HR Giger(09 of27)
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HR Giger, the artist who created the 'Alien' movie monster, died at the age of 74 on 12 May 2014. (credit:Derek Storm/Splash News)
Bob Hoskin(10 of27)
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Bob Hoskins died on 29 April 2014. After his death, his daughter penned a touching blog detailing lessons she learnt from her father. (credit:PA)
Edna Doré(11 of27)
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'EastEnders' actress Edna Doré died age 92 on 11 April 2014. (credit:Dave Hogan via Getty Images)
Mickey Rooney(12 of27)
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Mickey Rooneyv died in his sleep from natural causes on 6 April 2013. He was 93. (credit:Getty Images)
Frankie Knuckles(13 of27)
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House music DJ Frankie Knuckles died at the of 59 on 31 March 2014. (credit:Getty Images)
Clarissa Dickson Wright(14 of27)
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Clarissa Dickson Wright died on 15 March 2014 at the age of 66. (credit:PA)
Harold Ramis(15 of27)
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Comedy legend Harold Ramis died on 24 February 2014. He was 69. (credit:Getty)
Shirley Temple(16 of27)
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Iconic child star Shirley Temple died on 10 February 2014 in California. Her cause of death was not released. She was 85. (credit:AP)
Philip Seymour Hoffman(17 of27)
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Actor Philip Seymour Hoffman was found dead of an apparent heroin overdose on 2 February 2014 in New York City. He was 46 years old. (credit:Getty)
Phil Everly(18 of27)
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Musician Phil Everly, of the Everly Brothers, died aged 74 in California on 3 January 2014. (credit:PA)
Richard Atttenborough(19 of27)
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Richard Attenborough died just five days before his 91st birthday in August 2014. (credit:- via Getty Images)
Elaine Stritch(20 of27)
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Legend of both stage and screen, Elaine Stritch died in her sleep at her home in Michigan in July 2014. She was 89 years old. (credit:Walter McBride via Getty Images)
Alvin Stardust(21 of27)
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The 70s rocker died not long after being diagnosed with prostate cancer in October. (credit:Chris Jackson via Getty Images)
James Garner(22 of27)
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Star of 'The Notebook' and 'The Rockford Files', James died in July 2014. (credit:NBC via Getty Images)
Simone Battle(23 of27)
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Simone Battle, of US girl group GRL, died as a result of suicide in September. She was 25 years old. (credit:AP)
Clare Cathcart(24 of27)
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Actress Clare Cathcart, known for her role in ‘Doctors’ as well as appearances in ‘Call The Midwife’ and ‘New Tricks’, died at her home in Brighton at the age of 48 in September. (credit:Amanda Howard Associates)
Oscar de la Renta(25 of27)
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Fashion icon Oscar de la Renta, whose designs were worn by Jennifer Lopez, Sarah Jessica Parker and Naomi Campbell, died at the age of 82 in October. (credit:Danny Johnston/AP)
Billie Whitelaw(26 of27)
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The legendary actress died at the age of 82, in December 2014. (credit:Richard Blanshard via Getty Images)
Joe Cocker(27 of27)
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Joe died in December 2014, following a battle with lung cancer. (credit:KGC-138/STAR MAX/IPx)