Olympic heptathlon champion Jessica Ennis-Hill admits she would have doubts over Russian athletes if they are allowed to take part in the Rio Games later this year.
Russia is currently banned from international competition after a World Anti-Doping Agency report revealed "state-sponsored" doping in the country.
It remains to be seen whether an IAAF suspension will be lifted in time for Russia to participate when the Olympics come to Rio in August, but British star Ennis-Hill says the country would compete under a cloud of suspicion.
"I hope if it does get to that stage where there are Russian athletes competing in Rio in the Olympics, really drastic measures have been put in place to make sure that nothing like this happens again," Ennis-Hill told the BBC.
"I'd be lying if I would say that I wouldn't look at Russian athletes and think, 'Is everything 100 per cent OK?' because that's just natural for any athlete to feel like that after these different stories and situations have arisen."
Ennis-Hill, who won heptathlon gold in the 2012 Games in London, was beaten to gold at the World Championships in 2011 in Daegu by Russia's Tatyana Chernova.
Chernova was later banned when a sample from the 2009 World Championships was retested and revealed an anabolic steroid.
Ennis-Hill is still waiting to find out whether she will be upgraded to gold.
Chernova's results over a two-year period from August 2009 were annulled, but the period of disqualification expired two weeks before Daegu.
Chernova would not have had the qualifying standard for the 2011 event if her positive test had been discovered at the time, though.
Ennis-Hill was also shocked by the scale of the problems at the IAAF after the sport's world governing body was criticised by a second WADA report into doping released a week ago.
"As an athlete competing at this time, it's really awful to see and awful to read about, but at the same time you have to think that our sport has to go through this really terrible time," she said.
"It has to go to the very bottom, to the darkest place for it to then rise and come out the other side.
"There's been some really horrible stories to read. When you hear about what has been going on within the IAAF, within Russia, as an athlete it is just so disappointing.
"You put your faith and your confidence in organisations to make sure that the sport is governed well... and obviously that hasn't been the case. It needs to be addressed and it is a huge problem."