Boris Becker claimed Andy Murray is "totally out of order" for admitting he has been suspicious of his opponents doping in the past.
Wimbledon Champion Becker claimed the British No 1 is playing a dangerous game by wading into the debate on doping in tennis and insisted the sport is clean.
"We have random drug testing and unless it's proven, they are 100 per cent 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."