The Nigerian sprinter awarded a gold medal in the women's 100 metres final at the Commonwealth Games after Australia's Sally Pearson was disqualified has tested positive for a banned substance.

Osayomi Oludamola ran 11.32 to finish second to Pearson before the Australian was disqualified for a false start.

Commonwealth Games Federation (CGF) president Mike Fennell confirmed the result at a press conference in New Delhi on Monday afternoon (AEDT).

"Unfortunately I have to report to you that we have had a positive result," he said.

"[It is] in relation to the winner of the 100 metre women's runner."

Fennell named the substance as Methylhexaneamine, a banned stimulant, and said Oludamola has requested her B sample be tested.

"Any positive test, whether it's in a high-profile event or not, is something that is very much regretted."

Oludamola has kept her medal for the moment, but a provisional hearing held this afternoon by the CGF court decided that her provisional suspension would continue until the result of the B-sample is known. It is not expected for about 48 hours.

Fennell said more than 950 tests have been conducted with 700 results so far, but this is the first confirmed positive result of the Games.

After being asked how the doping result would affect the reputation of the Games, he replied: "Any positive test, whether it's in a high-profile event or not, is something that is very much regretted.

"We all strive for clean games, clean sport and clean competition.

"One doesn't know what sort of damage will accrue as a result of this particular test.

"But we just want to let everyone know that we are very vigilant with testing and the laboratory analysis is of the highest standard."

The Nigerian ran in the 200 metres yesterday and failed to qualify for the final.

But Nigeria's chef de mission Elias Gora said he knew nothing of the results.

"Nobody has approached me with that information," he said.

"Let it be said first. I am not going to pre-empt anything that has not come to me first."

He said he is still waiting for official conformation, but the reports are "unfortunate" and "disappointing".

Nigeria's Vanguard newspaper is reporting that a prescription medicine Oludamola took for a toothache may be the reason for the result.

'Devastating' disqualification

Friday night's race took just 11.28 seconds, but athletics officials spent four hours deliberating before deciding that Pearson should be disqualified for a false start following an appeal from the English team.

Pearson, nee McLellan, initially seemed to believe she had false-started, throwing her hands to her face and stopping on the track, only for the judges to turn their focus on another competitor.

Pearson was then allowed to take part in the re-start and was jubilant at her apparent win.

She draped herself in the flag, ran a victory lap, gave a television interview, and at one stage was allowed to start to walk out for her medal ceremony.

The appeal was quickly lodged and Pearson spent four agonising hours at the main stadium while argument raged.

Australia lodged a counter-appeal, but it was unsuccessful.

A weeping Pearson said she was "devastated" after the verdict was handed down.