A second Nigerian has failed a drugs test at the Commonwealth Games in Delhi.
Samuel Okon, who was sixth in the 110m hurdles behind England's Andy Turner, tested positive for the same drug as women's 100m winner Damola Osayemi.
Commonwealth Games Federation chief executive Mike Fennell says Okon has tested positive for methylhexaneamine, a stimulant that was only recently added to a list of banned drugs, the BBC reports.
Osayemi who has been suspended pending the analysis of her B sample
Mr Fennell said: "We are concerned with the number of incidents that are coming up with the same substance.
"At this stage I cannot speak very definitively as to where it's coming from but it appears that it may be coming from the use of supplements."
Asked when the results for Okon's B sample test would be known, Mr Fennell replied: "We have been informed that the athlete is waiving the right to the B sample (test) but this has yet to be confirmed."
