Federer calls for more tests
Roger Federer has called on tennis's governing bodies to start doing more to prevent doping in the sport.
Following Lance Armstrong's admission that he cheated his way to his seven Tour de France titles, a number of sports have come under criticism for not doing enough to tackle the issue.
Tennis currently only has limited tests, with just a few cases being reported in the last few years.
However, a number of competitors have been accused of committing an offence in recent times and Federer has called on the authorities to start introducing more stringent measures, just to give the players more piece of mind when they step onto the court.
"We should do more in terms of blood testing," said the 31-year-old. "It's important to make sure that tennis is credible and clean to a maximum.
"I feel tennis is very clean, there's maybe one case a year and they are not all done on purpose. Some are just mistakes, but stupidity can get you into trouble also."