Usain Bolt today refused to speculate on the failed drugs tests of fellow sprinters Asafa Powell and Tyson Gay.

Bolt, speaking ahead of the Anniversary Games, believes now is not the right time to discuss Jamaican Powell, who tested positive for the banned stimulant oxilofrine at national trials last month.

Powell is still waiting to discover whether analysis of his ‘B’ sample confirms the adverse finding.

American sprinter Gay also tested positive for the same stimulant in an out-of-competition test in May.

Bolt said: “There are a lot of details yet to be discussed so I’m just sitting and waiting to see the results and what’s what.

“There are a lot of things that haven’t been done and haven’t been said so I’m just waiting to see what is going on.”

However, the 26-year-old 100m and 200m world record holder admitted athletes have to be very careful with everything they eat or drink.

“In life you learn anything is possible,” Bolt said.

“You have to be very careful as an athlete because right now there are a lot of things on the banned list.

“You have to keep up to date all of the time. It’s hard but that’s why you have a team to help you out with this kind of thing.”

Asked if the public could trust him,

Bolt rolled his eyes and set about his now familiar refrain.

“I was hoping that question would come later in the day,” he said. “How long have you been following me - since 2008 maybe?

“If you were following me since 2002 you would know I’ve been doing phenomenal things since I was 15 and setting records all the time.

“I was made to inspire people and to run I was given a gift and that’s what I do. I’m going to continue running and using my talent and help the sport.

“I’m not going to stress about it (doping). I know I am clean and I just want to improve the sport and that is what I am going to do.”