BUTNER, NC -- Bernie Madoff looked ‘like someone had shot him in the stomach’ when he learned that his son had killed himself in a New York apartment, a former inmate at the Butner Federal Correctional Complex in North Carolina, told the New York Post.

“He was crying, and he was very distraught,” said the former inmate. "No one was messing with him. They knew what had happened."

Mark Madoff was found hanged in his SOHO apartment last Saturday,  exactly two years after his father's arrest.

Inmates assumed something was wrong when Bernie Madoff, who is serving a 150-year sentence for orchestrating an estimated $20 billion Ponzi scheme, was called to the prison’s chapel.

“Every time there's a death of a relative, you have to report to the chapel,"  said the former inmate.

Inmates initially thought Bernie Madoff’s call to the chapel involved his wife, Ruth Madoff.

"Everyone was speculating that someone might have killed his wife," the former inmate told the New York Post.

After returning to his cell, Berine Madoff went into a self-imposed exile for two days, said the former inmate.

"He didn't come out of his cell. He didn't even go to the chow hall," he said. "He didn't talk to anyone for a couple of days."

Eventually, Madoff emerged from his cell and was back to his normal routine by Tuesday, the former inmate said.

"He got back into the groove," he said. "He was getting back into prison time."

Read entire New York Post story here.