Investigators suspect actor Chris Penn's death was the result of natural causes or an accident because he had a prior illness and had taken drugs in the past, a coroner's spokesman said Thursday.

The 40-year-old actor was found dead in his Santa Monica condominium on Tuesday.

Penn had suffered from an illness and used multiple drugs in the past, said David Smith, a Los Angeles County coroner's spokesman. He declined to release details of the illness or say if the drugs were prescribed.

Medical examiners performed an autopsy Wednesday but won't know what caused Penn's death until toxicology tests are completed in about six weeks.

Penn was the younger brother of Academy Award-winning actor Sean Penn and musician Michael Penn. He appeared in numerous films, including "Reservoir Dogs," "Starsky & Hutch," "Rush Hour" and "Corky Romano."