Triple Olympic champion Marion Jones has admitted using steroids in preparation for the 2000 Sydney Games and plans to plead guilty on Friday to lying about her drug use, The Washington Post reported on Thursday.

Jones, who will also plead guilty to an unrelated financial matter in a New York court, made the admission in a letter she sent to close family and friends, The Post reported.

• The Magnificent Ms

According to the letter, Jones said she took the steroid known as "the clear" for two years beginning in 1999. She said in the letter that her former coach, Trevor Graham, gave her the substance, saying it was the nutritional supplement flaxseed oil.

Graham could not be reached for comment, while neither Jones's former attorney, Rich Nichols, nor her most recent coach, Steve Riddick, returned telephone messages seeking comment.

The sport's US governing body said it was not aware of Jones's letter or any pending legal action.

"Anything that exposes the truth about drug use in sport is good for ensuring the integrity of sport," USA Track & Field chief executive Craig Masback said in a statement.

"Any use of performance-enhancing substances is a tragedy for the athlete, their team mates, friends, family and the sport. We await any further developments on this matter."

Jones, 31, has previously denied using drugs designed to aid her performance.

The letter was read to The Post by a person who had been given a copy. A person familiar with Jones's legal situation, who requested anonymity, confirmed the relevant facts described in the letter, the newspaper said.

Jones said in the letter she expected to be sentenced to three months in jail for lying to federal agents, The Post reported.

'THE CLEAR'

She became the first woman to win five athletics medals at a single Olympics [Images] in 2000 when she captured gold medals in the 100 and 200 metres and 4x400m relay and bronzes in the long jump and 4x100m relay.

Jones could lose all five medals because of the admissions.

The International Olympic Committee in 2004 opened an investigation into allegations that Jones used performance-enhancing drugs.

An initial urine sample from Jones at the 2006 U.S. championships tested positive for the banned blood-boosting drug erythropoietin (EPO) but she was cleared when a second, backup sample was negative.

Jones has also been under scrutiny by the U.S. Anti-Doping Agency (USADA) in connection with the BALCO laboratory doping scandal but has never been charged with a doping offence.

She was accused by BALCO founder Victor Conte on national television of using performance-enhancing drugs.

She denied the accusation and sued Conte. The lawsuit was settled for an undisclosed amount.

'The clear,' the steroid tetrahydrogestrinone (THG) , has been at the center of the BALCO doping scandal involving athletes in a variety of sports.

It was previously undetectable until Graham provided the U.S. Anti-Doping Agency a sample in 2003.

Graham was indicted last year on three counts of making false statements to federal agents. He pleaded not guilty to the charges and his trial is scheduled for Nov. 26 in San Francisco.

(Writing by Steve Ginsburg in Washington and Gene Cherry in Raleigh)