Commonwealth Games women’s 100m gold medal winner Damola Osayemi has failed a drugs test.
Commonwealth Games Federation president Mike Fennell said Osayemi had asked for her B sample to be tested and a hearing would be held later on Monday.
The Nigerian, 24, was named champion on Thursday after Australia’s Sally Pearson was controversially disqualified for a false start.
It is the first negative test of the Games in Delhi.
The sprinter showed traces of a banned substance called methylhexaneamine, which has only recently been added to the World Anti-Doping Agency’s prohibited list.
If the test is confirmed, England’s Katherine Endacott, who finished fourth in the race behind Pearson and the Nigerian but was later awarded the bronze medal, would be elevated to a silver.
At the moment no decision has been made on the medals, pending the hearing.
The current silver medallist is Natasha Mayers of St Vincent and the Grenadines. If she were promoted that would be the country’s second ever Commonwealth gold medal.
Punishment can range from a warning to a two-year ban, although the medal would be forfeited if the B sample proves positive.
At his daily news conference, Fennell said: “Any positive test – whether in a high-profile event or not – is something that is very much regretted because we all strive for a clean Games, clean sport and clean competition.
We want a dope-free Games. If somebody is caught, action will be taken. At the same time it is a message that no-one can escape
Lalit Bhanot, the organising committee’s general secretary
“One doesn’t know what sort of damage will accrue but we want to let everyone know we are very vigilant and the testing is of the highest standard.”
Explaining why the news had been confirmed now, rather than waiting for the B sample, Fennell added: “We recognise there is difficulty in maintaining complete secrecy during the process.”
Lalit Bhanot, the organising committee’s general secretary, said: “We want a dope-free Games. If somebody is caught, action will be taken. At the same time it is a message that no-one can escape.”
Methylhexaneamine is the same drug the Indian weightlifter Sanamacha Chanu and swimmers Richa Mishra and Jyotsana Pansare were found to have used in September.
Wada subsequently moved it to the non-specified list, meaning it can be used with a therapeutic use exception certificate.
The Indians subsequently appealed against their bans but there has been no verdict yet.
According to companies that market products that contain methylhexaneamine, the drug stimulates the central nervous system.
It gives the body an energy boost by increasing the body’s metabolic rate.
Nigeria’s Athletics Federation president, Solomon Ogba, has reportedly claimed Osayemi was given prescription medicine to fight a nagging toothache.
“She took medication for her toothache and we strongly suspect that it was that, which led to her failed drug test,” he said.