The case in an American district court in Manhattan is expected to conclude in the next few days and those watching the soap opera unfold are wondering whether the reputation of Tim Montgomery can be tainted any further.

Five years ago, Montgomery briefly held the vaunted title of the world’s fastest man. He broke the 100 metres record in Paris, recording 9.78sec, and celebrated with his partner at the time, Marion Jones. His title, though, and the glamour of his union with Jones, a fellow US sprinter, was fleeting because three years later he was found guilty of doping and stripped of the record.

The downward spiral did not end there. Three weeks ago he pleaded guilty to charges of fraud and money-laundering and, after a plea-bargain, he will be sentenced to between 37 and 46 months in prison. Montgomery and 11 others were charged with participating in a scheme that involved banking counterfeit cheques worth $5 million (about £2.5 million). Court records show that one of these cheques, for $25,000, was deposited by Jones, although she was not charged. Aside from Montgomery, eight of the codefendants have pleaded guilty.

Montgomery’s lawyers have claimed that his was a “minor role”, although he will serve at least three years in prison. Allegations of a fuller part in the case arose when a codefendant opened his defence by blaming Montgomery for dragging him into the conspiracy, claiming that the former athlete had “started brokering kilo-quantities of drugs”.

In the present case, no drugs-related charges were laid against Montgomery and he has dismissed such allegations as “outlandish”. However, as the defence of his alleged co-conspirator mounts in the next few days, Montgomery will be observing from long distance whether mention of drugs resurfaces with any evidence.

The co-conspirator in question is Steve Riddick, who won a gold medal at the Montreal Olympic Games in 1976, and herein lies the tale. Riddick first met Montgomery when he coached him as an up-and-coming sprinter at Norfolk State University. He coached him again in 2005, when Montgomery and Jones were partners.

Given how far he has fallen, it takes some reminding that Montgomery and Jones so recently had exalted status in their sport. They were the fastest in the world, built a house together in North Carolina and had a son together in 2003, although by the time Riddick was working with them, the gloss had lost its shine.

Jones had been divorced from C. J. Hunter, the US shot-putter banned for steroid use. She and Montgomery had also been exposed for training in secret with Charlie Francis, the coach who had managed the drugs regime of Ben Johnson, the disgraced former Canada sprinter. And both were being tarnished by the rumbling of the Balco doping scandal.

Documents from the Balco laboratory in Burlingame, California, showed how its founder, Victor Conte, had masterminded Montgomery’s doping regime. Conte also went on the record about how he had personally supplied Jones with five different performance-enhancing drugs. Jones has persistently denied ever using them.

The Balco scandal resulted in Montgomery being banned from the sport. However, Jones survived and she would survive again a year ago, when a urine sample tested positive for EPO, after the B sample tested negative. Her approach since then appears to involve putting distance between herself and Montgomery, to the extent that she recently married Obadele Thompson, another sprinter, and announced that she was pregnant with his baby.

The same distancing has been the backbone of Riddick’s defence. Which leaves Montgomery, a notably shy man in a sport that breeds big personalities, at the bottom of the pile and on his own. “That’s what happens in this sport,” John Chaplin, the elder statesman of US athletics and the head track coach at the Sydney Olympics [in 2000], said. “You’re the greatest person in the world, but the minute you test positive everybody gets up and walks [away].

“Montgomery was a nice, quiet lad. He broke on to the scene briefly, but his career didn’t add up to much. And, like a lot of people who are told they are the greatest, he did stupid things.

“Once you have a taste of all that money, you might take a short cut to get it again, but all those nice people aren’t there for you any more.”

As for Montgomery, “he is remorseful and disappointed in himself”, Tim Heaphy, his lawyer, said. “He let himself and others down and he knows that.” Heaphy also said that “once this is past him, Tim could be a good businessman” and added that Montgomery took responsibility for the $25,000 cheque that went into Jones’s account.

The fittest survivor of the lot is probably Conte, who served four months in prison and is back selling nutritional supplements from the same building where Balco operated. “I’m a person who doesn’t break laws any more,” he said. He also claims a turnover of $300,000 a month. In prison, he said, he organised an athletics team. “My guys always won,” he said. Which may not be the case when Montgomery’s sentence starts.