The FBI is investigating whether a "criminal enterprise" played a role in the controversial jailhouse death of well-connected sex criminal Jeffrey Epstein, the head of the federal prison system told a Senate committee Tuesday.
But Bureau of Prisons Director Kathleen Hawk Sawyer also testified that there is "no indication, from anything I know," that the wealthy investor's demise on Aug. 10 "was anything other than a suicide."
The FBI did not immediately respond to CNBC's request for comment.
Sawyer's spokeswoman Kristie Breshears later told CNBC that, "When the Director referenced 'criminal enterprise', she was merely mirroring the language Senator [Lindsey] Graham used" in asking Sawyer whether the FBI was eyeing such an enterprise.
"She was referring to looking into possible criminal conduct by staff," Breshears said.
Sawyer's testimony before the Senate Judiciary Committee came on the same day that two guards from a Manhattan jail operated by the BOP were criminally charged with falsifying official records to cover up the fact that they never conducted mandated safety checks on Epstein and other inmates in the hours before he was found unresponsive with a noose around his neck in his cell.
Those guards, Michael Thomas and Tova Noel, allegedly browsed the internet and appeared to have been asleep for about two hours during the time that they were supposed to be making sure that Epstein was alive and accounted for.
Sawyer said Epstein's death is the one incident involving the BOP that has "probably gotten the most public attention."
"This incident was a black eye on the entire Bureau of Prisons," said Sawyer, who became the agency's director less than two weeks after Epstein died.
The New York City medical examiner's office has ruled Epstein's death was a suicide by hanging.
But Dr. Michael Baden, a forensic pathologist hired by Epstein's brother, has said that the injuries found on Epstein's neck were more consistent with those found in homicides.
That view has fueled conspiracy theories about Epstein's death, as have his connections to numerous rich, powerful and high-profile people, such as L Brands' Les Wexner, Microsoft's Bill Gates and Britain's Prince Andrew.
During Tuesday's hearing, one senator underscored to the prisons boss how skeptical many people are about the official ruling that Epstein killed himself.
"Christmas ornaments, drywall and Jerry Epstein. Name three things that don't hang themselves," said Sen. John Kennedy, R-La., flubbing Epstein's first name.
"That's what the American people think. And they deserve some answers," Kennedy said.
Graham, R-S.C., asked Sawyer about the probes into the incident, which are being conducted by the FBI and the BOP's Office of Inspector General.
"With a case this high profile, there has got to be either a major malfunction of the system or a criminal enterprise afoot to allow this to happen," Graham said.
"So are you looking at both? Is the FBI looking at both?" Graham asked.
Sawyer answered, "The FBI is involved, and they are looking at criminal enterprise, yes."
"I have received no information from the FBI investigation yet," she later said.
Sen. Ted Cruz, R-Texas, said it was "disgraceful" that Epstein died while in federal custody before getting an opportunity to testify about other influential men who might have been involved in his crimes.
Epstein "was a pedophile, he was a sexual predator who preyed on young girls, Cruz said. "There were powerful men that wanted Jeffrey Epstein silenced."
"As I see it there are two, and only two possibilities for what happened with Jeffrey Epstein," Cruz added.
"No. 1, there was gross negligence and a total failure of BOP to do its job with a prisoner on suicide watch that led to Epstein's committing suicide."
"Or No. 2, something far worse happened," Cruz said. "That it was not suicide but rather a homicide carried out by a person or persons who wanted Epstein silenced. Either one of those is completely unacceptable. Both of those are profound indictments of BOP and our federal incarceration system."
He then asked Sawyer if there was any indication that Epstein was the victim of a homicide.
"Based on the evidence that I am aware? No," Sawyer answered.
Weeks before his death, the 66-year-old Epstein was found semiconscious on the floor of his cell in the Metropolitan Correctional Center with marks on his neck.
He was placed on suicide watch after that incident for 24 hours, and then put under psychological watch for less than a week.
Epstein had been arrested in July after arriving at a northern New Jersey airport on a private plane from France.
Federal prosecutors in Manhattan charged him with the trafficking of dozens of underage girls to be sexually abused by him from 2002 through 2005 at his huge townhouse on the Upper East Side, and at his mansion in Palm Beach, Florida. He had pleaded not guilty in the case.
The arrest came six months after The Miami Herald published stories detailing how a number of women who claimed to have been abused by Epstein were not informed of a nonprosecution agreement that he negotiated with federal prosecutors in Miami in 2007.
Under that agreement, Epstein agreed to plead guilty to relatively minor state charges in Florida, which included paying an underage girl for sexual services.
In that earlier case, Epstein served 13 months in jail, but was out on work release for much of that sentence. He also had to register as a sex offender.
Epstein's plea deal occurred while Alex Acosta was U.S. attorney in southern Florida. Acosta went on to become Trump's Labor secretary and resigned from that position days after Epstein was arrested in July.
— Additional reporting by CNBC's Jim Forkin.