Prior to the afternoon of September 14, 2002, Tim Montgomery was regarded as gifted but erratic and some way short of fulfilling his obvious potential.

A few seconds in the modest Stade Charlety stadium at the Grand Prix final in Paris confounded the sceptics and transformed his life.

Montgomery, whose lawyers said on Tuesday he had received a letter from the U.S. Anti-Doping Agency alleging doping violations, shot to fame by setting a world 100 metres record of 9.78 seconds.

The mark was 0.01 of a second under fellow-American Maurice Greene's world record set five years earlier.

Of possibly more significance it meant Montgomery was now undisputedly the fastest man ever.

Canadian Ben Johnson clocked 9.79 seconds in the 1988 Seoul Olympics final but lost the gold medal and the time after he tested positive for a steroid.

Everything was in Montgomery's favour after he had settled into the starting blocks vacated by his off-track partner Marion Jones, the triple Olympic champion who had just won the women's race.

He anticipated the gun perfectly, with a reaction time of 0.104 of a second and was assisted by the maximum allowable following wind of two metres a second.

So unexpected was Montgomery's time that Moroccan 1,500 metre runner Hicham El Guerrouj was already giving a news conference to celebrate his confirmation as overall men's Grand Prix champion.

The complicated points system was hastily recalculated and Montgomery's world record proved just enough to give him the title and an extra $100,000.

JUNIOR RECORD

Montgomery, born in Gaffney, South Carolina on January 28, 1975, was initially a basketball and American football player.

He took up sprinting and, running on a grass track, clocked 9.96 to win the 1994 Juniors Colleges title, easily a world record for a junior.

"They said the track was three centimetres short but they measured in front of the 100 metres line," he said. "So then they ratified the world record."

Montgomery did not qualify for the 1996 Atlanta Olympics 100 metres team but ran in the heats for the 4x100 meters relay team which won the silver medal.

In the following year, Montgomery finished third behind Greene at the 1997 Athens world championships, sixth in Seville two years later and did not qualify for the 2000 Sydney Olympics, although once again he was alternate in the relay.

Montgomery enjoyed a fine 2001 season, winning the U.S. title and clocking 9.84 at the Bislett Games in Oslo.

He pushed Greene all the way at the Edmonton world championships, finished second in 9.85 to Greene's 9.82.

Then came 2002, the blossoming of his relationship with Olympic champion Jones and the world record, which allied to his win at the prestigious Zurich meeting, elevated him to world number one.

With Greene suffering increasingly from injury, Montgomery looked set to take over as world champion in 2003.

Instead his form went from bad to worse after the unwelcome publicity attracted by the ill-judged decision of Montgomery and Jones to team up with Johnson's old coach Charlie Francis.

He cut his European tour short after failing to make the final of a 100 metres at Crystal Palace but still started as one of the favourites at the Paris world championships, especially after Greene was injured in the semi-finals.

Instead, Montgomery was unable to take advantage, finishing fifth in 10.11. Kim Collins's winning time of 10.07 was the slowest since the inaugural World championships in 1983.

This year realistically represents Montgomery's last chance for an Olympic gold to confirm his place as a truly great sprinter.

Now his future is shrouded in doubt and, like Johnson, it is possible he could be remembered for all the wrong reasons.