American former 100-metre world record holder Tim Montgomery has pleaded guilty to heroin distribution charges at a federal court hearing.
Montgomery, who was once dubbed "the world's fastest man," appeared briefly before American judge Jerome Friedman.
The Sydney Olympic relay gold medallist was charged with conspiracy to possess with intent to distribute and distribution of over 100 grams of heroin.
Already serving a four-year prison sentence for his role in a cheque-fraud conspiracy, Montgomery faces a minimum of five years in prison on the heroin charge. His sentencing is set for October 10.
Montgomery, the former partner of Marion Jones, also could be fined up to $US2 million ($A2.1 million) and faces at least four years of supervised release.
According to the Drug Enforcement Administration (DEA), Montgomery sold 111 grams of heroin for nearly $US8,500 ($A8,840) to an undercover informant.
His ban from the sport also brought with it an order to return his Olympic medals, a gold he won in the 4 x 100-metre relay in Sydney in 2000 and a silver in the same event at the 1996 Atlanta Games.
Montgomery's world record-breaking 100 metre run of 9.78 seconds, set in Paris in 2002, also was erased from the historical lists.
