Tearful US track star Marion Jones said Friday she had broken the trust of her fans and announced she was retiring from the sport after admitting in court to taking steroids.

Marion Jones lowers her head while speaking to the media after leaving the US Federal Courthouse in White Plains, New York October 5, 2007. Triple Olympic champion Jones announced her retirement from athletics on Friday moments after pleading guilty to lying to federal investigators about her use of steroids.

"It is with a great amount of shame that I stand before you to tell you that I have betrayed ... your trust," the Olympic gold medal winner told a crowd gathered outside the courtroom in White Plains, New York.

Once ranked among the greatest athletes of all time, Jones has seen the clouds of doping gather until they have irrevocably tainted what should have been a glorious career.

Jones, 31, admitted in a US federal court that she had used the designer steroid THG from September 2000 to July 2001, ending years of angry denials of doping allegations.

Jones' confession came as she pleaded guilty to lying to a federal agent about her drug use, charge that could see her jailed.

The admission tarnishes Jones' greatest triumph - a five-medal performance at the 2000 Sydney Olympics, which ran from September 13-October 1 of that year.

It also made a mockery of Jones' vehement denials of doping over the past four years, as a woman once held up as the epitome of strength and grace tried to distance herself from disgraced associates and from evidence collected in the BALCO steroid distribution scandal that linked her to doping.

Long before she became the most successful female athlete at a single Games by winning three gold medals and two bronze at Sydney, Jones was recognized as an extraordinary sports talent.

At nine years old, she was a national sprint champion and at 16 her results earned her a spot as an alternate on the US 4x100m relay squad for the Barcelona Olympics.

She declined that berth, saying she preferred her first Olympic gold to come not as a mere extra in the heats but in a true finals victory.

Multi-talented, she was a standout basketball player at the University of North Carolina, where she studied communications and journalism, disciplines that helped provide the basis of her facility in dealing with the press.

A broken foot in 1995 prevented her from competing in the 1996 Atlanta Olympics, and in the wake of that setback she decided to focus on athletics and forego a possible basketball career.

Guided by C.J. Hunter, the shot putter she married in 1998, and Trevor Graham, the coach she began working with in April 1997, Jones reigned on the sprint track and in the long jump, posting 41 straight victories from 1997-98 in the combined disciplines.

Jones was virtually untouchable in 1998. In May she clocked a time of 10.71sec to become the second-fastest woman of all time over 100m, trailing only world record-holder Florence Griffith Joyner. Jones improved her best later that year with a time of 10.65.

Jones also established her personal best in the long jump in May of 1998 with a leap of 7.31m, good enough to put her among the top 10 performers in history. In September, she became the second-fastest woman ever in the 200m with a time of 21.62.

By the time Jones was being built up as the face of the Sydney Games, she owned three world titles, winning 100m and 4x100m world gold in 1997 and the 100m world title in 1999.

US broadcaster NBC vowed to follow her bid for an unprecedented five gold medals at Sydney "like a mini-series," but even as she triumphed the first clouds appeared on the horizon when Olympic officials announced that Hunter had tested positive for the steroid nandrolone earlier in the year.

Jones said she supported her husband, who never competed in Sydney and was later banned, and went on to complete her own historic Olympic campaign.

In 2003, Jones and the new man in her life, 100m world record holder Tim Montgomery, became the "fastest couple on the planet."

The pair had a son in 2003, Tim jnr, Jones absenting herself from the track that season.

By the time she returned in 2004, the BALCO investigation had led to the discovery of the so-called designer steroid THG, and linked the names of many prominent athletes, including Jones and Montgomery, to the lab's founder Victor Conte.

Montgomery was eventually stripped of his world record and banned based on evidence collected in the BALCO investigation, but insinuations about Jones - including allegations by ex-husband Hunter and Conte - repeatedly failed to stick.

She herself went on the attack, suing Conte over his doping accusations against her and vowing that she had "never, ever" taken banned drugs.

The battle appeared to take a toll, however, as Jones struggled on the track and saw invitations to prestigious meetings dwindle. A promising 2006 campaign was cut short by another doping incident, when it took a backup "B" sample test to clear her of using the endurance boosting hormone EPO.

USOC wants Jones to return Olympic medal

Marion Jones should immediately step forward and return the Olympic medals she won while competing in violation of the rules, US Olympics Committee Chairman (USOC)Peter Ueberroth said on Friday.

Jones' admission that she used steroids "is long overdue and underscores the shame and dishonor that are inherent with cheating," Ueberroth said in a statement e-mailed to Xinhua.

After years of denying that she used banned substances, Jones finally decided to come forward and admit the truth earlier in the day.

"Like any athlete who breaks the rules, Ms. Jones has earned whatever punishment the legal and anti-doping systems hand out," Ueberroth said.

"Her acceptance of responsibility does not end with today's admission, however. As further recognition of her complicity in this matter, Ms. Jones should immediately step forward and return the Olympic medals she won while competing in violation of the rules," Ueberroth said.

USOC Chief Executive Officer Jim Scherr also said Jones' admission marked a turning point in the fight against doping in sport, but it will not end here.

"In this new era of cooperation between legal authorities and anti-doping agencies, it is no longer a question of 'if' you will be caught, but rather 'when' and how severe the consequences will be," Scherr said.

He expressed the USOC's commitment to protect the integrity of sport and the health and well-being of the overwhelming majority of athletes who choose to compete clean.

"Under no circumstance will doping ever be tolerated by the United States Olympic Committee, and we are committed to making certain the team we take to the 2008 Beijing Games is clean," he said.
 
(Agencies via CRI.cn, Xinhua News Agency October 6, 2007)