Fallout from the death by apparent suicide of the disgraced financier Jeffrey Epstein in a New York jail cell intensified on Sunday, as authorities in three separate jurisdictions opened investigations into the death and accusers expressed outrage at not being able to confront Epstein in court.

Epstein, 66, was accused of sex trafficking crimes going back to the early 2000s involving dozens of women and girls as young as 14. His body was discovered by staff at the Metropolitan correctional center in Manhattan at 6.30am Saturday morning, the facility said.

New York City’s chief medical examiner said late on Sunday night that an autopsy had been carried out but more information was needed to determine the cause of death.

Dr Barbara Sampson said in a statement that a city medical examiner performed the autopsy on Sunday while a private pathologist observed the examination at the request of Epstein’s representatives. The private pathologist, Dr Michael Baden, was the city’s chief medical examiner in the late 1970s and has been called as an expert witness in high-profile cases including by the defense at OJ Simpson’s 1994 murder trial.

According to an unnamed city official cited by the New York Times late on Sunday night, Sampson was “confident” Epstein died by hanging himself in the jail cell.

The FBI, the inspector general’s office of the US justice department and the New York City medical examiner’s office have all opened investigations into why Epstein, who had been placed on suicide watch for a week last month, had not remained under special monitoring.

On the night before Epstein was found dead, a pair of guards at the jail failed to follow procedures that would have required a visual check-in on him every 30 minutes, New York Times quoted an unnamed law enforcement official as saying. The jail is understaffed, a labor union said, and one of the guards was working his fifth straight day of overtime while the other had been forced to work overtime.

Epstein was found dead about 24 hours after court documents in a related case shed new light on his alleged crimes. The documents were gathered as part of a defamation case brought against former Epstein associate Ghislaine Maxwell, the daughter of the publishing tycoon Robert Maxwell. The suit was settled in 2017. Lawyers for Maxwell did not reply to media requests for comment.

Court documents described how Epstein allegedly groomed girls for rape and sexual abuse, recruiting the victims at schools or, in one significant case, at Mar-a-Lago, Donald Trump’s Florida resort.

Epstein, who owned a Caribbean island, a private jet and who traveled abroad frequently, was deemed a flight risk at a court hearing last month and denied bail. He last appeared in court two weeks ago.

One accuser, Jennifer Araoz, said Epstein raped her when she was 15 years old, after she was recruited outside her high school in New York.

The Metropolitan Correctional Center jail in Manhattan where Jeffrey Epstein was found dead on Saturday morning. Photograph: Jeenah Moon/Reuters

Araoz said in a statement after his death: “I am angry Jeffrey Epstein won’t have to face his survivors of his abuse 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. Epstein is gone, but justice must still be served.”

Attorney general William Barr, who as head of the justice department has authority over the federal facility where Epstein died, announced the inspector general’s inquiry on Saturday.

“I was appalled to learn that Jeffrey Epstein was found dead early this morning from an apparent suicide while in federal custody,” Barr wrote. “Mr Epstein’s death raises serious questions that must be answered.”

But Barr’s statement was at odds with Trump, who late on Saturday retweeted a conspiracy theory tying Epstein’s death to the financier’s relationship with Bill Clinton, a sometimes guest aboard Epstein’s plane. After Epstein was arrested last month at a New Jersey airport upon his return from France, Clinton released a statement denying any impropriety.

Trump was criticized for spreading the conspiracy theory. “This is another example of our president using this position of public trust to attack his political enemies with unfounded conspiracy theories,” presidential candidate Beto O’Rourke, the Texas congressman, said on CNN.

Federal prosecutors vowed to continue to pursue the case, despite Epstein’s death. Investigators are examining Epstein’s extensive network of social and professional contacts – which included luminaries in the fields of academic science and the law, as well as politics and business – weighing whether further charges might be warranted.

Epstein’s circle of friends and acquaintances has included Donald Trump; Bill Clinton; Prince Andrew, the Duke of York; Leslie Wexner, the founder of the company that owns Victoria’s Secret ; and many other prominent names in law, entertainment and politics.

The first allegations of sexual abuse came in 2005 when a woman contacted the Palm Beach police, alleging her 14-year-old stepdaughter had been taken to Epstein’s mansion by an older girl. The girl was allegedly paid $300 to strip and massage Epstein.

That triggered an 11-month investigation that drew in the FBI. Interviews with alleged victims and witnesses showed that some of the girls involved were under 18.

“Today’s events are disturbing, and we are deeply aware of their potential to present yet another hurdle to giving Epstein’s many victims their day in court,” said Geoffrey Berman, the US attorney in Manhattan, in a statement Saturday. “To those brave young women who have already come forward and to the many others who have yet to do so, let me reiterate that we remain committed to standing for you, and our investigation of the conduct charged in the indictment – which included a conspiracy count – remains ongoing.”

Lawyers for Epstein said they were “enormously sorry to learn” of their client’s death.

“No one should die in jail,” said the lawyers, Reid Weingarten, Marty Weinberg and Michael Miller. “We cannot confirm rumors as to his cause of death, and we trust that the United States attorney’s office and the United States Marshalls will thoroughly investigate the circumstances of today’s tragedy.”

After original attempts to prosecute Epstein collapsed, Trump’s former labor secretary Alex Acosta came under repeated scrutiny for being seen as too lenient when he oversaw the case.

In February, a judge ruled prosecutors in the case violated the law by concealing the deal from his underage alleged victims. Acosta resigned from his administration post in July.

As Epstein’s world unraveled, some of those who had sought his financial investment advice came forward while many more preferred to distance themselves, issuing statements painting their interactions in minimal terms. They included Trump and Clinton, who both issued statements saying they had had little to do with Epstein in recent years.

Wexner said this week that the financier had “misappropriated” more than $46m of his personal fortune. He said money went missing a decade ago, according to a letter to the Wexner Foundation.

“We discovered that he had misappropriated vast sums of money from me and my family,” Wexner said in the letter. “This was, frankly, a tremendous shock, even though it clearly pales in comparison to the unthinkable allegations against him now.”