Disgraced sprinter Tim Montgomery has admitted using performance-enhancing substances before running in the triumphant US 4x100m relay team at the 2000 Sydney Olympics.

Montgomery, in jail having been sentenced to almost nine years imprisonment on heroin charges and for a check fraud, made the admission in an interview for the HBO TV show "Real Sports with Bryant Gumbel" scheduled to be broadcast on Tuesday.

"Prior to the 2000 Olympic Games in Australia I broke the rules," said Montgomery, 33, in a transcript provided by HBO.

"I used (substances to boost my) testosterone and then I used HGH (human growth hormone) four times a month. I have a gold medal I'm sitting on that I didn't get with my own ability."

Two years after the Games, Montgomery set a 100m world record of 9.78 seconds that was later erased after the US anti-doping agency found he had received steroids. He was barred from competition in 2005.

Montgomery's HBO admission could have further ramifications.

The International Olympic Committee made the US men's 4x400m relay team give up their medals after Antonio Pettigrew admitted doping.

Medal-winning relay teams in Sydney that included Marion Jones, Montgomery's former girlfriend, had their results wiped out after Jones was found to have violated doping rules.

(Agencies via China Daily November 26, 2008)