World 100-metre record holder Asafa Powell says he is convinced he will race against drug cheats at this year's Beijing Olympics, reports said on Sunday.
Amid claims by the former head of the World Anti-Doping Agency, Dick Pound, that Beijing will be the cleanest Olympics in history, the world's fastest man said he has his suspicions.
The Jamaican has refused to name those of his rivals he suspects but is adamant anyone who tests positive should be banned for life.
"I have a lot of suspicions but I keep them to myself," Powell told Melbourne's Sunday Herald Sun newspaper.
"It's always going to be there, that dark cloud, because people are wondering who is really on drugs.
"It's a very unfair sport. I get my satisfaction from beating whoever I think is on it.
"They should be banned. They're doing something illegal and when you do something illegal you should be punished. So I would say yes, give them a life ban."
Beijing's anti-doping centre, one of only 33 in the world approved by WADA, will conduct tests on nearly half the 11,000 Olympic competitors at a rate of 230-240 tests a day during the Games.
That is 25 percent more than at the last Athens Games and nearly double the number in Sydney 2000.
Powell, who is recovering from a cut knee which stopped him from competing at the Sydney Grand Prix meet on Saturday, is hoping to return to the track for Thursday's IAAF meet in Melbourne.
The 25-year-old Jamaican, who won the Melbourne Commonwealth Games gold medal in 2006, said he has a point to prove after faltering at the world championships in Osaka last year.
He was the favourite in the final but gave way when challenged by American Tyson Gay and finished third.
"I need to stay focused and not repeat mistakes," Powell said.
"As soon as you make a mistake, someone is there to come on to you.
"I can produce my fastest time. It's just for me to do the same thing that I do in other competitions in the major championships.
"This year I'm very strong, running a lot faster than last year. I just want to go out there and put in the hard work and see where I'm at.
"I'm used to running sub-10s ... so if I can go below 10 for the first race that will be really good," said Powell, who holds the world record of 9.74 seconds.
"It's the first race (in Melbourne), so I don't know what to expect. I've just got to try my best."
Powell has not competed since October but said he has been drug tested in December and January.