R&B singer Sean Levert collapsed in his cell at Cuyahoga County Jail, in Cuyahoga County, OH. on Sunday night and died one hour later, but further investigation into his death may be sought by his family, according to recent media reports.

TMZ.com reports that Sean Levert, the son of O’Jays vocalist Eddie Levert, was physically restrained by jail guards right before he died. Staff at the Cuyahoga County Jail told TMZ that Levert was “out of control” and “hallucinating,” which determined them to place him in a restraining chair so he would not hurt himself or others.

Jail warden Kevin McDonough said Levert was cooperative and “went willingly” when jail staff bound his wrists and shackled his feet.

The 39-year-old Levert collapsed in his cell on Sunday night and was taken to the hospital, where he was later pronounced dead. He was behind bars for failing to pay more than $80,000 in child support to the mother of his children. The singer had pleaded guilty. He had served one week of his one-year, 10-day prison sentence.

The Cuyahoga County Coroner said an autopsy was inconclusive, but added that foul play had been ruled out. There were no signs of trauma on the singer’s body. The coroner said that Levert suffered from high blood pressure and had been hallucinating in jail.

Jail officials said they had not been aware of any pre-existing medical condition that could have helped prevent the singer’s death.

Toxicology reports could take four to six weeks, the coroner added.

Levert was one third of 1980s trio Levert. His older brother (and former member of the band) Gerald Levert passed away in November 2006, at age 40, following an accidental drug overdose.

In a statement released on Monday night, the Levert family said, “There is no song that can capture the loss that we have in our hearts.”

The family is reportedly asking the FBI to investigate what happened, according to TMZ.