PHILADELPHIA — A Ukrainian hockey coach was found dead of a suspected suicide while in custody in Philadelphia on child-molestation charges, a U.S. prison official said.

Ivan Pravilov, 49, was found unresponsive in his cell at 3 a.m. Friday, according to spokesman Darrin Howard of the Federal Detention Center in Philadelphia.

A preliminary FBI investigation suggested the death was a suicide, Howard said. An autopsy is pending.

Pravilov was a mentor to several NHL and U.S. college players, including Dainius Zubrus of the New Jersey Devils, who played for him as a teen in Ukraine.

Other former players have said his methods included physical, emotional and sexual abuse.

“For 10 years, he brainwashed us every single day,” former player Maxim Starchenko said Friday after learning of the death. Starchenko, 33, of suburban Detroit, wrote a recent book about Pravilov called “Behind the Iron Curtain: Tears in the Perfect Hockey `Gulag.”‘

“He got away with it too easy. I wanted to look him in the eye in the courtroom and just ask him, `Just what were you thinking all these years?”‘

Pravilov ran an elite hockey school in Ukraine from the 1980s until about 2007, when he came to the U.S. to run camps for standout players from the U.S. and abroad. Players from Ukraine and elsewhere typically enrolled for about a month, staying with host families and traveling with Pravilov to various U.S. cities for tournaments and clinics.