NEW YORK – Attorney General William Barr personally questioned the last inmate to share a cell with Jeffrey Epstein before the multimillionaire sex offender died by suicide, a source told the New York Daily News.

Epstein was found hanging from cloth tied to a bed frame early on Aug. 10, 2019, rocking the highest levels of the Justice Department. Investigators’ attention turned to Efrain “Stone” Reyes, who had been transferred out of a cell he shared with Epstein the day before the suicide at the Metropolitan Correctional Center in lower Manhattan.

Reyes’ niece and other sources previously told the Daily News that Reyes was moved to the privately run Queens Detention Center, which holds cooperating witnesses.

Following Epstein’s death, Reyes was pulled from the privately run jail for frequent meetings with authorities, according to a source. Following one of the meetings, Reyes told the source that the attorney general himself had asked questions about the staff at MCC.

“Barr wanted to know about what was going on in there. Barr told him, ‘I owe you a favor, thank you for telling us the truth,’” said the source, who became close friends with Reyes while they were both held at the Queens jail.

“He said (Barr) was a good guy. Barr was nice about it. He just wanted to know if (inmates) were being mistreated. What (Reyes) believed happened. Just basically that. He told them everything. He cooperated with Barr.”

The unusual sit-down between the country’s former top law enforcement official and the cooperator who confessed to participating in a drug ring at Bronx housing projects illustrates the significance of the feds’ failure in the Epstein case.

A Justice Department spokesman declined comment. The New York Times reported weeks after Epstein’s death that Barr was personally overseeing four inquiries into Epstein’s suicide. Barr has said he was “livid” after the death.

“If in fact the attorney general personally interviewed Jeffrey’s prison drug-dealing roommate that would be a real jaw dropper. … there are only a million levels between the a.g. And the fbi agent who should have done the interview (I am exaggerating but only by a little),” Epstein’s attorney Reid Weingarten wrote in an email to the Daily News. “If it is true the question is why in the world was Barr so personally interested in what happened to my client?”

Two MCC correctional officers, Tova Noel and Michael Thomas, have pleaded not guilty to sleeping on the job and falsifying records the night of the suicide. An attorney for Thomas, Montell Figgins, told the Daily News he wouldn’t be surprised if Barr directly questioned Reyes, given how the case was handled by the Justice Department.

The News exclusively identified Reyes as Epstein’s final cellmate last month. The 51-year-old caught coronavirus at the Queens Detention Facility earlier this year, was released in April and died last month at his mother’s Bronx apartment.

The source contacted the Daily News seeking to dispel conspiracy theories that Reyes’ death had something to do with Epstein.

The source said Reyes was deeply troubled by the suicide and did not hesitate to help investigators.

“With the Epstein thing, he was dealing with it. He was having nightmares,” the source said.

“He thought if he would’ve stayed a little longer maybe he wouldn’t have did what he did. The whole time, he would tell (Epstein), ‘Don’t do that in the cell. I don’t need you doing that. Don’t need that on my conscience.’”

The source recalled a conversation between Reyes and Epstein.

“Stone would be like, ‘What’s it like having all that money?’ ” the source said.

“(Epstein) just said he’s had a good life. He was very blessed.”

The Bronx drug dealer and Coney Island-born sex offender worth $634 million overcame their differences.

Reyes struggled with sleep due to drug addiction. Epstein preferred to be asleep by 10 p.m., the source said. So, the financier supplied Reyes with drugs that cost $500 a pop to put him to sleep. The source believed the drug was Suboxone.

“What do you need, how can I help you so you go to bed and turn the lights out?” Epstein said, according to the source close to Reyes.

“He paid for stuff for him to keep him occupied, you know? He’s had his problems with drugs. He had bragged that Jeff spent $500 – and another $500 – so he’d go to bed early.”

MCC has a well-established reputation of being overrun with contraband.

The source, who also came down with COVID-19 at the private jail, had no doubt Reyes’ demise was connected to the effects of coronavirus.

“With Stone, he would constantly say, ‘I don’t feel the same, I don’t feel right, I don’t move the right way no more,’” the source said. “You see people saying conspiracy things. No – he got COVID. He was having lung issues. He would cough all the time.”

As coronavirus ravaged the Queens Detention Facility earlier this year, jail staffers gave inmates, including Reyes and the source, takeout from Popeyes Chicken and expanded the number of channels available on television, the source recalled. At one point, Reyes and the source watched a documentary about Epstein, who was able to cultivate relationships with some of the most powerful men in the world while allegedly running an international child sex trafficking scheme.

“(Reyes) was like, ‘I just didn’t see that from him. I didn’t see that side of him. I never pictured him being with young girls. Some guys like that are creepy,’ ” the source recalled. “He said he never really got that side of Epstein – like he was someone who took advantage of girls. But we all have our secrets, you know? You never know.”