Investigators said Boris Tarasov, thought to be 61, was found dead in his Moscow apartment after neighbors complained of an odor, RIA Novosti reported Monday.
Tarasov had been dead for two to three weeks before his body was found, a statement posted on the Investigative Committee website said.
A preliminary inquiry into his death was opened, although investigators said they didn't find evidence of foul play at the scene.
Tarasov was involved in the investigation in the early 1990s into the actions of the eight hard-line, high-level Communist Party leaders who tried to oust Gorbachev and stop his perestroika reforms.
For the last several years, Tarasov was the host of court show "Sud Idyot" (Court in Session), a Russian version of the U.S. show, "The People's Court."