“With all the money that we have in the sport, you would think that there would be more funding for the anti-doping programme,” Federer told the Times. “I would like to see more funding [for testing], no doubt about it, especially in the off-season. This is when the players work the hardest.

Switzerland's Roger Federer lies on court after falling during his match against Canada's Milos Raonic Image credit: Reuters

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“The best way is that you get tested every quarter-final that you play in a tournament. You know there will be testers there when the prize money and the points go up, you know you will be tested. I think for the players’ minds and for the fans, it would be a good thing to have.”

There had been reports earlier in the week that drug testing did not take place at some of the 2016 tournaments. The ITF's anti-doping programme has an annual budget of $4 million (about £3.2 million).

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