Abel Xavier football player 2007
In 2005, while playing for Middlesbrough, Abel Xavier was suspended from football for 18 months after testing positive for using the anabolic steroid methandrostenolone (dianabol) Stephen Dunn/Getty Images

European football's governing body, Uefa, insists professional football does not have a drug problem, after a study it commissioned found 1-in-12 top players had suspiciously high levels of testosterone, consistent with the use of anabolic steroids. The tests were conducted among top-level players from international teams and top leagues including the Premier League.

The study – the largest ever conducted into doping in the game – collected 4,195 urine samples from 879 players at the European Championships, Champions League matches, and players in top-tier leagues in England, Spain, Italy and Germany between 2008-2013. Of those tested, 68 players (7.7%) recorded levels which would trigger an investigation under newly-introduced Uefa rules.

None of the players will be investigated because the tests were taken anonymously. However, former Southampton striker and England international Graeme Le Saux, now a Football Regulatory Authority board member, said the results were eye-opening. He told the Sunday Times: "It's a problem that the whole of Europe is going to have to work together to tackle."

Michel Platini urges Sepp Blatter to quit
Uefa chief Michel Platini. The organisation has dismissed suggestions many top players are taking steroidsReuters

After being given the findings by the Sunday Times and the German broadcaster ARD/WDR Professor Julien Baker from the University of the West of Scotland, said the results suggested football has a significant problem. Baker, who has investigated steroid misuse for 20 years, said: "If the findings are accurate then this sheds light on previously untold levels of suspected cheating in Europe's top competitions."

Uefa said other factors, including alcohol, might explain the results. In a statement Uefa said: "This study does not present any scientific evidence of potential doping in football especially due to the presence of confounding factors, the lack of standardisation procedures among the 12 laboratories and the quantification of steroid profiles when the samples were collected."

The statement continued: "Uefa has had a very thorough anti-doping programme for many years with over 2,000 tests a year and only two occurrence of positive tests, both for recreational drugs, which proves that doping in football is extremely rare. Uefa has now implemented a new steroid profiling programme which has come into operation at the start of the 2015/16 season."