The athletes - four men and one woman - do not include Bolt or Asafa Powell, the former world 100m record holder who finished sixth tonight.

 

 

Bolt said: "I'm not sure who it is yet, I'm sure it's not me so I'm not really worried.

 

"If it's someone from my group I don't know, I can't comment.

"Definitely it's sad to know there are still drugs [in the sport] but for me it doesn't really matter, as long as I'm clean I'm just going forward.

"It's sad for the sport because the sport was getting on so well, I was trying to bring it back.

 

"This is probably a step backwards because people start questioning everybody, especially from Jamaica.
 

"For me it doesn't matter because I will be going out there, day after day, doing my best.

 

"I get tested all the time. It shows that people get tested and they get caught if they are on drugs.
 

"Sometimes you move forward and you take one step back.

 

"It's hard but I'm trying my best to push the sport forward.

 

"I think after a while people will notice that you can't get away with it and they'll stop, but for now I guess we can't do anything about it."

 

Bolt, the triple Olympic champion and world record-holder, won the 100m in London in 9.91sec into a headwind of 1.7 metres per second, thrillng a capacity crowd of 16,000, including several thousand Jamaican supporters based in London.

 

Fellow Jamaican Yohan Blake was second in 10.11. 

 

Bolt said: "I feel really good about going to Berlin [for the World Championships next month] and I'm going there on a mission.

 

"I'm just glad I got through the race injury free.

 

"My start wasn't the best but I'm improving and I now have more work to do.

 

"I'm in really good shape right now and I don't see any reason to run myself out.

 

"I did well and was proud of myself. I got it right so I'm happy."

 

Bolt is confident of being in top form for the World Championships.

 

He said: "I'm still at 85 per cent [fitness] and after this it's all training.

 

"I've got two or three weeks of good training to put in.

 

"So I guess I will be 100 per cent by Berlin."

 

But the drugs issue dominated events.

Powell said: "It's their bad luck, it's not for me to worry about, it doesn't affect me one bit.

 

"People might be saying bad stuff now but it doesn't really bother me."

The International Association of Athletics Federations (IAAF) earlier confirmed news of the positive tests.

 

IAAF spokesman Nick Davies said: "We have just received the paperwork from Jamaica, it is five - four guys and one girl.

 

"These are in-competition tests.
 

"We now inform the [Jamaican] federation who will then inform the athletes and then they are asked if they want the B-sample tested.

 

"It's very, very early in the process so we cannot say who they are or what the substance is."