Marion Jones’s letter of confession is astonishing because she says that she is finally telling the truth, yet there is evidence aplenty to suggest that she is not and that the real facts are far more condemning.

Jones says that, for two years, she took tetrahydrogestrinone (THG) unknowingly, under the misconception from her coach, Trevor Graham, that it was flaxseed oil. She also says that she never knowingly used any other banned performance-enhancing substances.

However, weigh up that assertion against the following extract from an interview given in December three years ago by Victor Conte, the pharmacist with whom Jones’s highs and lows are inextricably linked: “I was sitting in an Embassy Suites hotel room in Covina, California, about a foot away from Marion. The next day [April 2001], she was going to try to break the world record in the 300 metres. It was her first competition of the 2001 season and we were both excited.

“She came to my room for a new piece of equipment I’d brought, a $1,000 NovoPen injector that looked like a Sharpie [marker pen] and can be used for human growth hormone (HGH). I needed to teach her how to use it. Marion wasn’t the least bit nervous; she’s always in control. She pulled the Spandex of her bicycle shorts above her right thigh. She dialled up a dose of 4½ units of HGH and injected it into her quadriceps.”

Against revelations as nakedly detailed as that, it is mighty hard to believe Jones. However, we should perhaps consider Conte’s own words with suspicion as he has served a prison sentence for the illegal nature of his involvement in the careers of Jones and various other athletes. Indeed, by next year it seems that the entire main cast in Jones’s extraordinary life may all have been behind bars.

In her letter, Jones says that she started taking THG – unknowingly - in 1999. In fact, she started working with Conte the next year when he became a close part of her team, alongside Graham, her coach.

Conte was a former bassist with the 1970s band Tower of Power who had, for some years, been running a Californian pharmacy, the Bay Area Laboratories CoOperative (Balco), that sold athletes’ supplements. Conte also devised banned drugs, of which THG was his most notorious, and masterminded systems to keep his clients ahead of the antidoping authorities.

Conte would thus communicate regularly with Graham who that same year introduced Tim Montgomery, another of his athletes, to Conte; they saw Montgomery as having fantastic potential and devised a project to make him the fastest man in the world. Jones would later marry Montgomery, though first she had to split with her first husband, C. J. Hunter. Hunter, a hostile, monosyllabic shot putter, took much of the shine off Jones’s five-medal “triumph” at the Sydney Olympics in 2000 by being exposed as a drugs cheat midway though those Games.

It was because of this association that Jones started to have to deal with a regular media inquisition into whether she herself was “clean”. That questioning intensified two years later when she and Montgomery left Graham and took a decision, which back-fired disastrously, to work in secrecy with Charlie Francis, a coach known throughout the sport for the fact that he was the mastermind of the drugs regime of Ben Johnson.

By this stage, Montgomery was not only Jones’s partner but also world record-holder and she was getting increasingly slick and aggressive in dealing with the media and what she declared to be an unjust obsession with doping. The questioning, however, intensified four years ago when Balco was raided by police; first she was exposed as a Balco client, then Conte started blowing the whistle and Montgomery got banned and stripped of his world record. Though Jones attempted to sue Conte, she ceased to be credible as a clean athlete.

Yet she objected and objected. Her own autobiography, published three years ago, deals with the issue in a single page, the whole of page 173 being filled with large red letters, declaring: “I have always been unequivocal in my opinion: I am against performance-enhancing drugs. I have never taken them and I never will.”

Strangely, one person who managed to locate sympathy in his soul for Jones yesterday was Conte. “I don’t feel any sense of vindication,” he said. “I feel sad for Marion. Is she a bad person? No. Marion made mistakes. The pain and suffering she is about to endure in public is going to be devastating to her.” Indeed it is. Though the pain and suffering she has caused to her sport is pretty devastating, too.

Main players in game of deceit that shocked the world

Marion Jones

Played basketball at university but turned to athletics and became the 100 metres world champion in 1997, her first year on the professional circuit. Her “Drive for Five” medal hunt at the Sydney Olympics won her three golds and two bronzes. Arguably the most talented female athlete of all time; indisputably a talent abused.

Victor Conte

The brains behind Balco. Found guilty on one count of conspiracy to distribute steroids and a second count of laundering a portion of a cheque. Spent four months in prison last year and another four on house arrest. Back selling supplements but swears they are all clean.

Trevor Graham

No coach in world sport has had more athletes test positive. Was banned last year by the US Olympic Committee from using its facilities. Goes on trial next month for perjury and apparently a cast of athletes are lining up to testify against him. It was he who anonymously sent a syringe of THG to the antidoping authorities in 2003; his former athletes are, understandably, unhappy with that.

Tim Montgomery

Stripped of his world 100 metres record when found guilty of doping. More recently was found guilty for involvement in money-laundering. Is due to be sentenced next month and faces up to 46 months in prison.