Banned drugs were found in over 3800 drugs test carried out in 2014, according to figures released by the World Anti-Doping Agency.
283,304 tests were carried out across the year, and the results represent a 10% drop in failed tests, but WADA claims that more than one in 10 elite athletes could be using performance-enhancing drugs.
WADA opened an investigation into doping in August following allegations that a third of medals won at Olympic Games and World Athletics Championships between 2001 and 2012 were by athletes with suspicious test results.
As well as a drop in samples containing banned substances, there was also a fall in tests requiring further investigation.
