Autopsy says Pettigrew committed suicide

American Antonio Pettigrew, who was stripped of a 2000 Olympic 4x400m relay gold medal for doping, committed suicide with a sleep aid overdose, according to an autopsy report released Wednesday.

The report by the North Carolina state medical examiner's office said the cause of death was diphenhydramine toxicity.

Another report ruled the case a suicide and the likely toxic agent as the sleep aid Unisom, which the National Institutes of Health says contains diphenhydramine.

A bottle of the pills was found with the 42-year-old Pettigrew when his body was recovered from inside his locked car in Chatham County on August 10.

Pettigrew, who won the 1991 400-meter world title in Tokyo, was a member of the 4x400m American relay team that won the gold medal at the 2000 Sydney Olympics.

But the International Olympic Committee (IOC) stripped Pettigrew and his teammates -- including legend Michael Johnson — of their medals after he admitted, during a trial against former coach Trevor Graham in 2008, to doping.

At the time of his death, Pettigrew was an athletics coach at the University of North Carolina.