Disgraced sprinter Marion Jones has accepted a two-year ban after admitting she used performance-enhancing drugs, the US Anti-Doping Agency has announced.

Jones, who told a US court on Friday that she had taken the banned substance known as the "clear" from September 2000 through to July 2001, has also handed in the five medals - three gold and two bronze - she won at the Sydney Olympics in 2000.

Jones had long been associated with the BALCO laboratory, that has been at the centre of US sport's biggest doping scandal, with both first husband CJ Hunter and subsequent boyfriend Tim Montgomery being banned after failing doping tests.

Despite this Jones spent years protesting her innocence before pleading guilty to being in violation of International Association of Athletics Federations and USADA rules on Friday. The 31-year-old also pleaded guilty to two counts of providing false statement to federal investigators and will be sentenced in January.

US Olympic Committee Jim Scherr said Jones had been disqualified from all competitive events on and subsequent to September 1 2000 forfeiting all medals, results, points and prizes from that date. In addition to her five Olympic medals, Scherr said he believed Jones' 2001 World Championship medals, a gold and a silver from the 100 and 200m respectively, should also be forfeited.

It is expected that the USOC will request the return of more than $100,000 in funds Jones had received, while the IAAF is also expected to seek millions of dollars in prize and appearance money from Jones.

Greece's Katerina Thanou, who has since served a two-year doping ban and is awaiting trial for perjury over the mysterious motorbike accident that prevented her and compatriot Kostas Kenteris from attending a dope test before the Athens Olympics, finished second behind Jones in the 100m in Sydney, with Jamaica's Tayna Lawrence in third.

In the 200m Bahamian Pauline Davis-Thompson was runner-up to Jones followed by Susanthika Jayasinghe of Sri Lanka and Beverly McDonald of Jamaica. Russia's Tatyana Kotova could move up to bronze in the long jump.

The US Olympic Committee chairman, Peter Ueberroth, has urged its 2000 Olympic women's relay teams to hand in their medals in light of the new development.

"We do not think that the relay medals were won fairly and we urge the athletes to return their medals," Ueberroth said. "We don't have jurisdiction in that matter. If we did, we would be on the side of returning the medals.

"It's our opinion any sporting event where something is won unfairly is completely tarnished and [medals] should be returned. The relay events were won unfairly."

France finished fourth behind the bronze-medal winning US in the 4x100m relay, while Jamaica, Russia and Nigeria followed the Americans home in the 4x400m.

In addition to Jones, two more of the American 4x100m relay team have served doping bans since 2000. Chryste Gaines served a two-year ban due to her involvement in the BALCO clinic case, while Torri Edwards was banned for the use of stimulant nikethamide in 2004 and served 15 months of her two-year suspension before the substance was downgraded by the World Anti-Doping Agency.

Ueberroth also said letters of apology had been sent to 205 national Olympic committees, the people of Australia and the organisers and competitors of the 2000 Games.

"We have written a letter of sincere and humble apology to the 205 national Olympic committees and in addition, a more extensive letter to the people in Australia, apologising to the organisers, the volunteers and the Australian people," he said. "This event should not be tarnished by what has happened."

Ueberroth added that the USOC "sincerely apologised to athletes denied a podium place and denied the chance to hear their national anthem and see their flags" before going on to pledge that the US team would be drug-free at next year's Beijing Olympics.

"We pledge that the 2008 Olympic team will be completely clean - that is our pledge," he said. "There is never any absolute guarantee but that is our pledge ... it is our clear endeavour and absolute priority."

Jones' two-year ban started on Monday - the day she accepted the suspension.

Pippa Davis / Eurosport