Amid questions about how suspect in a major sex trafficking investigation was not placed on suicide watch – and as the internet filled with conspiracy theories – attorney general William Barr, announced the FBI and the justice department’s prisons’ inspector would be probing how the 66-year-old was able to apparently take his own life while awaiting trial in New York.

“I was appalled to learn that Jeffrey Epstein was found dead early this morning from an apparent suicide while in federal custody,” said Mr Barr.

“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.

Officials in New York confirmed that the suspect had been found dead alone in his cell on at around 7.30am on Saturday morning at the the Manhattan Correctional Centre in New York City.

Jeffrey Epstein: Controversies surrounding paedophile billionaire Show all 9 1 /9 Jeffrey Epstein: Controversies surrounding paedophile billionaire Jeffrey Epstein: Controversies surrounding paedophile billionaire Jeffrey Epstein in court Billionaire financier Jeffrey Epstein attends court as he pleads guilty to solicitation and procuring a person under the age of 18 for prostitution, 2008 Zuma/Rex Jeffrey Epstein: Controversies surrounding paedophile billionaire Jeffrey Epstein in court Billionaire financier Jeffrey Epstein pleaded guilty in 2008 to felony solicitation and procuring a person under the age of 18 for prostitution. He was sentenced to 18 months in jail. Epstein, allegedly paid several girls under the age of 18 in return for naked massages at his Palm Beach, Florida estate Zuma/Rex Jeffrey Epstein: Controversies surrounding paedophile billionaire Jeffrey Epstein's car Jeffrey Epstein is whisked away from the Palm Beach County jail in a black car shortly after 6am on 22 July 2009. Epstein left the jail through the sally port, where prisoners are brought in, rather than through the main doors where prisoners are routinely released Zuma/Rex Jeffrey Epstein: Controversies surrounding paedophile billionaire Jeffrey Epstein's mugshot Billionaire Jeffrey Epstein's mugshot, taken after he was indicted for soliciting a prostitute on 26 July 2006. Beginning in mid-March 2005, Epstein became the target of a sexual battery probe conducted by the Palm Beach Police Department, according to the affidavit, which alleges that Epstein paid a series of underage girls to engage in sexual activity with him. In a 2002 New York magazine profile of Epstein, Donald Trump called the moneyman a 'terrific guy' who 'likes beautiful women as much as I do, and many of them are on the younger side.' Epstein, who reportedly runs a multibillion-dollar investment fund, travels in his own Boeing 727 (upon which he has transported Bill Clinton to Africa) and owns a 45,000-square-foot mansion on Manhattan's Upper East Side Palm Beach County Sheriff's Department Jeffrey Epstein: Controversies surrounding paedophile billionaire Jack Goldberger, Jeffrey Epstein's attorney Jeffrey Epstein's attorney, Jack Goldberger, talks with reporters gathered outside the Palm Beach County jail on 22 July 2009 after Epstein was whisked away from the jail in a black car Zuma/Rex Jeffrey Epstein: Controversies surrounding paedophile billionaire Jeffrey Epstein Florida Police department sexual offenders database picture of Jeffrey Epstein taken in 2013 Jeffrey Epstein: Controversies surrounding paedophile billionaire Jeffrey Epstein's mansion His Palm Beach mansion in Florida Google Jeffrey Epstein: Controversies surrounding paedophile billionaire Jeffrey Epstein's island The private Caribbean island, Little St James is part of the US Virgin Islands NBC News Jeffrey Epstein: Controversies surrounding paedophile billionaire Jeffrey Epstein's island The private Caribbean island, Little St James is part of the US Virgin Islands NBC News

Multiple media reports said sources at the facility said it appeared he had killed himself. Last month, Epstein was found unconscious on the floor of his jail cell with marks on his neck, according to media reports, and officials were investigating that incident as either a possible suicide attempt or else assault.

There was no immediate explanation for why the ex-financier was placed not under special watch after that incident. The New York Times said Epstein had been placed under special surveillance after the July 23 episode, and received a daily psychiatric evaluation. He was then removed from suicide watch on July 29, it said.

Among those to express dismay as to how Epstein was able to kill himself, was New York congresswoman, Alexandria Ocasio-Cortez.

“We need answers,” tweeted Ms Ocasio-Cortez, a member of the House of Representatives’ oversight and reform committee. “Lots of them.”

Epstein was being held at the facility after being arrested and charged last month with sex trafficking charges that accused him of abusing dozens of underage girls as young as 14. Epstein had been charged with one count of sex trafficking conspiracy and one count of sex trafficking with underage females, and had pleaded not guilty.

NBC coverage from 1992 shows Donald Trump and Jeffrey Epstein discussing women at Mar-a-Lago party

Those charges came 11 years after Epstein’s lawyers cut a plea deal with prosecutors in Florida to avoid a similar charge.

As controversy over that plea deal mounted last month following the new charges, the lawyer who oversaw the deal, Alexander Acosta, who went on to become Mr Trump’s labour secretary was forced to stand down.

His death came a day after new legal documents unsealed by a court, provided more details about the numerous young girls Epstein is said to have abused over several decades.

The documents, relating to a defamation lawsuit brought by Virginia Giuffre, who said she was abused by Epstein and members of his circle over a number of years. Among those she claimed she was told to have sex with were, former New Mexico governor Bill Richardson, financier Glenn Dubin, former senator George Mitchell and modelling agent Jean-Luc Brunel. All have denied the claims.

Also contained in the documents were accusations by another alleged victim, Johanna Sjoberg, who said Britain’s Prince Andrew touched her breast while sitting on a couch inside Epstein’s Manhattan apartment in 2001.We need answers. Lots of them.

Buckingham Palace has repeatedly insisted the allegations about the Duke of York are “categorically untrue”, despite the men remaining friends even after Epstein served jail time for a 2008 plea of sex with an underage girl.

Reuters said at the NYC facility where Epstein was held, two jail guards were required to make separate checks on all prisoners every 30 minutes, However, for some reason, that procedure was not followed overnight, according to a source. The financier was in a cell by himself when his body was found.

Despite Epstein’s death, the sex trafficking investigation being carried out by federal authorities, will continue reports said. In a court filing on July 25, the government said it was pursuing an “ongoing investigation of uncharged individuals” in connection with the case against Epstein. Nebraska senator Ben Sasse, a Republican member of the Senate judiciary committee, wrote in a scathing letter to Mr Barr that “heads must roll” after the incident.

“Every single person in the Justice Department….knew that this man was a suicide risk, and that his dark secrets couldn’t be allowed to die with him,” he said.

Ms Giuffre’s lawyer, Sigrid McCawley, said Epstein’s suicide less than 24 hours after the documents were unsealed “is no coincidence”. She urged authorities to continue their investigation, focusing on Epstein associates who she said “participated and facilitated Epstein’s horrifying sex trafficking scheme”.

Others who had accused Epstein, reacted to the news with frustration that the financier will not have to face them in court.

“We have to live with the scars of his actions for the rest of our lives, while he will never face the consequences of the crimes he committed the pain and trauma he caused so many people,” accuser Jennifer Araoz said in a statement.

Brad Edwards, a Florida lawyer for nearly two dozen other accusers, said that “this is not the ending anyone was looking for”.

”The victims deserved to see Epstein held accountable, and he owed it to everyone he hurt to accept responsibility for all of the pain he caused,“ Mr Edwards said in a statement.

Florida senator Marco Rubio said on Twitter that “scrutiny of how Epstein was able to commit suicide is warranted”.

He added: “But the immediate rush to spread conspiracy theories about someone on the “other side” of partisan divide having him killed illustrates why our society is so vulnerable to foreign disinformation and influence efforts.”

Cameron Lindsay, a former warden who ran three federal prisons, said the death represented “an unfortunate and shocking failure, if proven to be a suicide”.

“Unequivocally, he should have been on active suicide watch and therefore under direct and constant supervision,” he said. “When you have an inmate as high profile as Epstein, it’s absolutely imperative the warden set the tone with his or her leadership to ensure these kinds of incidents don’t happen.”