Cincinnati, Aug 18 (IANS): Multiple Grand Slam winner Roger Federer said the sport of tennis cannot afford to tolerate Australian Nick Kyrgios' behaviour adding that the Association of Tennis Professionals (ATP) should "come down hard" on the controversial 20-year-old.

Kyrgios was fined $12,500 by the ATP and further punishment may still be forthcoming after he jibed at his opponent, World No.5 Stan Wawrinka of Switzerland during a match in Montreal last week that "(Thanasi) Kokkinakis banged your girlfriend. Sorry to tell you that, mate".

The comment did not go down well in the international tennis circuit.

"We all agree that he definitely crossed the line by a long shot. We're not used to that kind of talk in tennis. I know in other sports it's quite common, maybe normal. Not in our sport, really. It's normal that the tour comes down hard on him and explains to him that it's not the way forward," Federer was quoted as saying by cincinnati.com on Monday.

A 17-time Major winner, Federer added, "Clearly the behaviour was very disappointing and not great for the sport, one that many players have tried to build up and make it a good image, build up a good image. We want kids to be wanting to get into this sport because it's a nice sport."