King of Infomercials' Don Lapre Slit Own Throat with Razor

King of Infomercials" Don Lapre died from a self-inflicted razor blade wound to the neck, law enforcement sources tell TMZ.

We're told jail guards found piles of blood-soaked clothing lining Don's bed in his Arizona jail cell. Sources say ... officials believe Don used the clothing to conceal the bleeding in order to thwart efforts to save his life.

Lapre was found dead in his cell Sunday morning. The autopsy was completed yesterday.

As we previously reported, Don's mother claims her son had been treated for severe depression after the TV pitchman was jailed in a vitamin fraud case. She also claims jail officials took away his meds, which may have played a role in his apparent suicide.