The Jamaican athletics team has had an "extremely unusual" number of doping tests in Beijing, the team's chef de mission Don Anderson has claimed.
"We are concerned this could have a serious effect," he said after seeing his squad tested 32 times in five days.
"There has been an exceedingly long list of tests and we find this extremely unusual."
Sprinter Asafa Powell has already claimed that the amount of blood taken could leave him weak for his events.
Anderson has said that there is more testing at this year's Olympics than in previous events.
"It is a major concern to us and they (testers) have taken a lot of blood," he said.
"This is not a protest but we are just saying that it is rather unusual."
However IOC spokeswoman Giselle Davies said the organisation had not received any complaints.
"We have a very comprehensive doping programme," said Davies.
"If athletes have any concerns they should raise them with the authorities."
Powell has already complained that drugs testers had come calling so often and taken so much blood that it may hamper his 100m final run.
He said team mates Michael Frater and Usain Bolt, the current 100 metres world record holder, were also under constant scrutiny from testers.
BBC OLYMPICS BLOG"They've tested me four times here; they're taking so much blood I'll be weak for the final," explained the former 100 metres world-record holder.
Beijing aims to be dope-free with extra checks being used to avoid drug cheats.
"I'm almost sure I might be tested again. I don't know about anyone else but they're really doing it in my case and with my team-mates Michael Frater and Usain Bolt," added Powell.
"They're saying they're doing about 4000 tests. It's just very difficult to catch everyone but I hope they can do it and make this Olympics clean."
Athletes in China will be the most tested in history because of the stringent measures, with authorities paying particular attention to the sprinters after recent doping revelations.
Athens' winner Justin Gatlin of the US is currently serving a four-year ban for doping offences.
Compatriot Tim Montgomery, a winner in the 4x100m relay in Sydney, was a client of BALCO, the San Francisco laboratory which produced the designer steroid THG.
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