A study by UEFA has fed suspicions that the use of anabolic steroids in football's elite is widespread, according to German public television broadcasters ARD and WDR.

Significant testosterone values were found in 7.7 percent of the 879 players whose urine samples were tested by researchers, the two broadcasters reported. They explained that this could possibly be due to doping with anabolic steroids.

UEFA said it cannot draw definitive conclusions from the study and the players will not face any consequences, since the tests were anonymous.

In addition, sports scientist Perikles Simon warned that the statistical basis of the study is unclear. It is not obvious whether the significant values can really be attributed to external factors, i.e. doping.

However, British researcher Julien Baker, who is an expert in doping, does not share his opinion. "If the results are correct, then it is very alarming. It would demonstrate that in some of the major European competitions steroids are widely used", he said. Football seems to have a "significant problem", he added.

On UEFA's request, 4,195 urine samples were tested from the years 2008-2013, from players who mostly played in the Champions League and Europa League.

Scientists from twelve antidoping laboratories in Europe worked on the study. According to data from ARD, UEFA has expanded its doping analysis system in the meantime so that manipulations with long-term steroids can also be demonstrated.