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."
Murray is one of the most outspoken players on the Tour about doping and welcomed Maria Sharapova's recent ban for taking banned substance Meldonium.
In an interview with the Mail On Sunday Murray said: "I have played against players and thought, 'They don't seem to be getting tired.' Have I ever been suspicious of someone? Yeah. You hear things."
But Becker, who coaches world No 1 Novak Djokovic, insisted all the top players are clean, to the best of his knowledge.
"It's a very dangerous subject. I can only repeat that tennis is clean. I believe 100% Andy is clean," said Becker, speaking at the Laureus World Sport Awards, "Roger is clean, Rafa (Nadal) is clean, Stan (Wawrinka) is clean, all these guys are clean.
"There was always a suspicion of Rafa and I find that so unbelievably disrespectful about one of greatest players of all time.
"I can only speak for Novak and believe me he gets tested a lot! That can mean twice in a Grand Slam.
"In Melbourne he got tested in the first week and the second week. He would be playing a match at night and somebody comes to his hotel room at 7am to do a urine test and I think, 'how dare you.' But those are the rules."