Channel 4's Dispatches last night stated that a large number of top footballers have failed tests for cocaine, ecstasy and cannabis.
The report revealed that Garry O'Connor, while at Birmingham City, was banned after testing positive for cocaine. A number of other professional footballers were also named.
It was claimed that a number of cases have been covered up, while hundreds of doping tests have been missed over a three-year period.
In response to the programme, PFA chairman Gordan Taylor said: "Not so long ago I went to a Premier League club and spoke to a player who up until January had been tested 15 times that season.
"Our top players are tested many times by FIFA, UEFA and domestically."
The Football Association have also denied covering up dozens of positive test results.
