MOSCOW, Russia — With a number of high-profile athletes testing positive for banned substances in their system, former 2011 IAAF 100m world champion Yohan Blake is leaving nothing to chance and won’t trust anyone, not even himself.

Blake, who was forced to watch from afar as training partner and compatriot Usain Bolt won the men’s 100m gold at the 14th IAAF World Championships at the Luzhniki Stadium here a week ago, while rehabbing his injured right leg, said he is not willing to take any chances.

He was addressing a press conference with journalists from several countries at a Moscow hotel on Friday, and while refusing to be drawn into the discussion on the failed drug tests by fellow Jamaicans Asafa Powell and Sherone Simpson, he said athletes “have to be really careful and know the people who are around you”.

Blake’s advice to athletes was not to even trust themselves. “You can’t trust anyone, not even yourself; when in doubt make sure everything you take is being tested (at a laboratory).”

Powell and Simpson were among five Jamaican athletes who tested positive at the recent JAAA National Trials and are awaiting a hearing after their ‘B’ samples confirmed the positive results from the ‘A’ samples.

Discus throwers Traves Smikle and Allison Randall, as well as a junior athlete also tested positive.