Six-time Grand Slam champion Boris Becker has claimed that Andy Murray is "out of order" for suspecting some of his opponents of doping.
Murray recently admitted that he has questioned opponents in his mind if they do not seem to get tired on the court.
The British number one also claimed that there is regular suspicion because "you hear things", but Becker, who is the coach of Novak Djokovic, is not taking the comments lightly.
"We have random drug testing and unless it's proven, they are 100% innocent," Becker told the Daily Mail.
"So to throw in a curve ball and assume something because somebody has won a Grand Slam or is fitter I think is totally out of order.
"Andy is one of the fittest players on the tour. He often outlasts other players and nobody is questioning his ethics."
Last month, Maria Sharapova announced that she failed a drug test after her loss to Serena Williams at the Australian Open in January.
