Jamaican sprinter Asafa Powell has blamed his failed drug test on supplements given to him by a new physio, with whom he has only been working for two months.

It was revealed yesterday that Powell and female Jamaican sprinter Sherone Simpson both tested positive for the same banned stimulant.

The athletes contacted the World Anti-Doping Agency this week to request a police raid on the hotel where they had been staying with their new physio, Chris Xeureb.

Over 50 substances were taken to be tested at a laboratory in Italy following the raid and the athletes' United States-based manager, Paul Doyle, thinks that it has been a mistake rather than knowingly cheating by all parties.

"I think that's probably the case [that Xuereb was unaware what the supplements contained] but, at the same time we couldn't take any chances so we [kept him unaware of the police raid]," Doyle told The Telegraph.

"Once we knew of the positive test, we realised that Asafa and Sherone were the only two athletes in the group who had been given new supplements by this physio.

"Asafa's probably had 150-200 clear tests in the past. He starts working with a new physio who gives him new supplements and all of a sudden he has a positive test in his first test. Obviously something was in the new supplements. So we immediately asked WADA to go in there and search everything."

Former 100m world champion Tyson Gay also tested positive for a banned substance yesterday.