The FBI and the Inspector General are investigating after billionaire paedophile Jeffrey Epstein was found dead in his jail cell after apparrently taking his own life.

The New York Post reports that a gurney carrying Epstein was wheeled out of the Manhattan Correctional Centre around 7:30am (9:30 AEST) and headed to New York Downtown Hospital.

Paramedics tried to revive Epstein as they wheeled him into the hospital but were unsuccessful.

The medical examiner's office in Manhattan confirmed Epstein's death.

A call for a reported cardiac arrest came in at 6:38am, Fire Department sources said.

Two weeks ago, Epstein, 66, was placed on suicide watch after he was found nearly unconscious in his cell with injuries to his neck.

There was some question about whether the incident was a suicide attempt or an assault, and investigators noted that the marks on his neck were "more consistent with being choked than hanging yourself," a source told the New York Post.

Department of Justice spokesman Lee Plourde refused to say whether that incident was ruled a suicide attempt or an assault.

He said Epstein was never treated outside MCC after that incident, disputing reports.

"He was never taken to the hospital," he said.

The New York Times reported that he was taken off suicide watch at the time of his death.

Mr Plourde confirmed that Epstein was not "currently" on suicide watch in his cell.

The billionaire financier was being held without bail pending his trial on child sex-trafficking charges.

Some reports suggest cameras inside the Manhattan Correctional Centre malfunctioned around the time of his suicide.

The MCC has some of the tightest security in the US and has housed notorious criminals including Joaquin "El Chapo" Guzman, mob boss John Gotti, the World Trade Center bombers and Ponzi scheme mastermind Bernie Madoff.

Attorney General Bill Barr said he was "appalled" to learn Epstein was able to commit suicide in his federal jail cell.

"Mr Epstein's death raises serious questions that must be answered. In addition to the FBI's investigation, I have consulted with the Inspector General who is opening an investigation into the circumstances of Mr Epstein's death," Mr Barr said.

Epstein was busted on July 6 over the alleged sexual abuse of dozens of young girls in his Upper East Side townhouse and his waterfront mansion in Palm, Beach, Florida, between 2002 and 2005.

He pleaded not guilty and faced up to 45 years in prison.

Many people on social media started to question how he was able to kill himself.

Epstein's arrest last month launched separate investigations into how authorities handled his case initially when similar charges were first brought against him in Florida more than a decade ago.

US Labor Secretary Alexander Acosta resigned last month after coming under fire for overseeing that deal when he was US attorney in Miami.

The 66-year-old had pleaded not guilty.

His death came as thousands of documents were unsealed on Friday in connection with a defamation case against his alleged recruiter revealed dozens of high-profile names that a self-identified victim, Virginia Giuffre, said she was forced to perform sex acts with, from former Maine Senator George Mitchell and ex-New Mexico Governor Bill Richardson, money manager Glenn Dubin and MIT professor Marvin Minksy.

The financier once boasted about having high profile friends, including US President Donald Trump, former US president Bill Clinton and Prince Andrew.

In 1992, Mr Trump directed Florida businessman George Houraney to organise a "calendar girl" competition at Mar-a-Lago. After 28 female contestants were procured, he revealed that the other guests were just "him and Epstein", The New York Times reported.

Then, in a much-quoted 2002 New York Magazine interview, Mr Trump described Epstein as a "terrific guy" and even acknowledged that he liked women "on the younger side".

"I've known Jeff for 15 years. Terrific guy. He's a lot of fun to be with. It is even said that he likes beautiful women as much as I do, and many of them are on the younger side," he told the magazine.

Last month, Mr Trump said he had not spoken to Mr Epstein for 15 years.

"I knew him like everybody in Palm Beach knew him," Mr Trump said. "I was not a fan."

WHO WAS JEFFREY EPSTEIN

Epstein lived on a 100-acre private island in the Caribbean and one of the biggest mansions in New York valued at $US56 million.

A college dropout, he started as a physics and mathematics teacher at the pristigious Dalton School in the Upper East Side of Manhattan.

While teaching at the school, Epstein became acquainted with Alan Greenberg, the chief executive officer of investment bank Bear Stearns, whose son and daughter were going to the school, and who offered him a job as a low-level junior assistant to a floor trader in 1976.

He moved up the ranks and started advising the wealthiest clients.

He was reportedly asked to leave Bear Sterns for unknown reasons in 1981 but remained close with Mr Greenberg and his sucessor Jimmy Cayne.

He founded his own consulting firm, Intercontinental Assets Group, that same year and in 1988 founded his own financial management firm, J. Epstein & Company. The company was formed to manage the assets of clients with more than $US1 billion in net worth.

One of those clients was Leslie Wexner, chairman and CEO of L Brands and Victoria's Secret.

Wexner trusted Epstein so much he gave him power of attorney to run his finances.

He is said to have dated publishing heir Ghislaine Maxwell, whom he had met by 1991. Maxwell was implicated by several of Epstein's accusers as procuring or recruiting underage girls in addition to being his girlfriend.

If you are experiencing mental health issues or suicidal feelings contact Lifeline on 13 11 14 or BeyondBlue 1300 224 636. If it is an emergency please call 000.

This article originally appeared in the New York Post and is republished here with permission