Tyson Gay and Asafa Powell fail drugs tests American 100-metre record holder Tyson Gay and Jamaican former 100m record-holder Asafa Powell have failed drugs tests - meaning both men will now not compete at next month's World Championships in Moscow. Gay dropped the bombshell yesterday, announcing that he had tested positive for a banned substance and would be pulling out. Powell's agent, Paul Doyle, confirmed he also had tested positive for a banned substance. Powell was reportedly one of five Jamaicans to have tested positive, according to the Jamaican Gleaner newspaper. Gay would not reveal the substance, but he said he was notified by the US Anti-Doping Agency (USADA) late last week that a sample came back positive from a 16 May out-of-competition test. He said he will have his "B" sample tested soon, possibly as early as this week. I don't have a sabotage story. I don't have any lies. I don't have anything to say to make this seem like it was a mistake or it was on USADA's hands, someone playing games," said Gay, who fought back sobs as he spoke. I don't have any of those stories. I basically put my trust in someone and I was let down. Asked who that person was, Gay replied: "I can't really say it. Sometimes a human being naturally, generally trusts somebody. That's what people do. A triple world champion in 2007, Gay returned to full fitness again this season after being plagued by hamstring and groin ailments, along with a surgically repaired hip. He won the 100m and 200m at the US national championships last month, setting up an eagerly anticipated battle with Usain Bolt at the worlds. But that showdown has now been scrubbed. Powell ran his world record of 9.72sec in 2008 but has often failed to live up to expectations. He said: "My attitude towards doping regulations and testing is well-known and I willingly give samples whenever requested. This result has left me completely devastated in many respects. Professionally, this finding fully negates any possibility of me being a part of Jamaica's contingent of athletes competing at the World Championships in Moscow later this summer. Gay, who has been in Amsterdam, also said he will pull out of a Diamond League meeting in Monaco and fly back to the headquarters of USADA in ­Colorado Springs, Colorado, to be on hand when his "B" sample is tested. A few years ago, Gay was part of USADA's program called "My Victory," where athletes pledge to compete clean. In his testimonial on the ­website, Gay said, "I compete clean because I ­really believe in fairness, and besides that, my mom would kill me! Just being honest. He has spoken with his team-mates, friends and family, including his mother and daughter. "They already know it is some type of accident, or some type of - I don't want to use certain words, to make it seem like an accident, because I know exactly what went on, but I can't discuss it right now," he said. In a statement, USA Track and Field chief executive Max Siegel said: "It is not the news anyone wanted to hear, at any time, about any athlete." He added: "We do not know the facts of this case and look to USADA to adjudicate it and handle it ­appropriately."