Warsaw - All 160 players tested ahead of Euro 2012 as part of an anti-doping programme returned negative samples, European football's organising body UEFA said on Sunday.
Ten players from each of the 16 teams were tested in pre-competition tests, in which blood and urine samples were taken.
"In addition, the haematological and hormonal profiles from the analysis conducted in all the samples show that there is absolutely no prevalence of blood or hormonal manipulation among players participating in the competition," UEFA said.
During the tournament, all 31 matches will be subject to controls, with four samples after each match taken by UEFA's doping control officers. Unscheduled tests will also take place in rest periods between matches.
Samples are being analysed by Warsaw's Institute of Sport laboratory, which is accredited to the World Anti-Doping Agency (WADA).
Pre-competition tests carried out before Euro 2008 in Switzerland and Austria returned similar results as this year.
Follow Sport24 on Twitter and Facebook
24.com publishes all comments posted on articles provided that they adhere to our Comments Policy. Should you wish to report a comment for editorial review, please do so by clicking the 'Report Comment' button to the right of each comment.
No interest, this is supposed to be the soccer off-season!
Some intrigue, will watch the odd match
Some of the best players in the world doing what they do best. Of course I'm excited...
View Results | Vote Archive
7% No interest, this is supposed to be the soccer off-season!
25% Some intrigue, will watch the odd match
68% Some of the best players in the world doing what they do best. Of course I'm excited...
Vote Archive
GEN De La Rey says the Stormers have had a pretty bad run when it comes to refs, assistant refs and TMO calls this season. He says such glaring ref errors have no place in the professional game.
Twitter Follow Sport24 on Twitter
Newsletters Sign up for Sport24's Morning Glory newsletter
Blogs Yes your opinion counts. Get it out there
WIN Enter and win with Sport24!
Mobile Sport24 on your mobile phone - WAP, alerts, downloads, services
BlackBerry Stay in the loop on your BlackBerry
iPhone Latest Sport24 news on your iPhone
Facebook "Like" Sport24's Facebook page
TV schedule Plan your couch time with our searchable sport TV guide
RSS Feeds Sport news delivered really simply.