Washington - Disgraced former sprint star Tim Montgomery has admitted to doping ahead of the Sydney 2000 Olympics and appears ready to return his gold medal he won there in the 4x100 metres relay.

However, it remains unclear whether the IOC can strip the whole relay team of the gold which would mean that doping would have cost the US all three relay golds from Sydney.

The former world record holder Montgomery, 33, admitted to using the steroid testosterone and Human Growth Hormone (HGH) ahead of the Millennium Games in an interview with the HBO television network to be broadcast on Tuesday.

"I used testosterone, and then I used 9GH (human growth hormone) four times a month," Montgomery said.

"I have a gold medal that I'm sitting on that I didn't get with my own ability ... I'm not here to take away from anybody else's accomplishments, only my own. I apologize to the other people that was on the relay team if that was to happen."

Montgomery never failed a doping test but was implicated in the investigation around the Californian Balco lab.

He was banned for two years in 2005 and was stripped of his then world record 9.78 seconds he ran 2002 in Paris.

Montgomery only ran in the heats of the Sydney relay but got a gold medal like all other team members led by Maurice Greene.

The International Olympic Committee stripped the US of the women's 4x400m gold and 4x100m bronze medals after Marion Jones, Montgomery's former finace, admitted to doping. The men lost their 4x400m gold when Antonio Pettigrew said he used forbidden substances.

But the IOC has an eight-year statute of limitations. Montgomery's statements come more than eight years after the Sydney Games ended on October 1, 2000.

US Olympic committee spokesman Darryl Seibel was quoted as saying that Montgomery should return his medal.

Montgomery is currently serving a prison sentence of more than eight years for cheque fraud and heroin selling. (dpa)