Ex-doping chief: FIFA performed extra tests on Russia 2014 World Cup squad
FIFA's former chief medical officer has admitted that the governing body conducted additional drug tests on Russia's squad for the 2014 World Cup amid allegations of a state-sponsored doping program.
Professor Jiri Dvorak told BBC Sport that all testing was performed within the confines of FIFA's anti-doping regulations and all tests returned negative results.
Dvorak's admissions come days after the publication of the Garcia Report, a 359-page report penned by former FIFA independent ethics investigator Michael Garcia that inspected allegations of voting corruption for the 2018 and 2022 World Cup bids.
Related: FIFA releases leaked Garcia 'corruption' report
Suspicions of a widespread Russian doping regime stem from the release of the McLaren report, which suggested that more than 1,000 athletes from no fewer than 30 sports had samples covered up or altered. FIFA has since refused to say if any of the athletes targeted by the McLaren Report are members of Russia's 2014 World Cup squad.
According to Dvorak, the substance in question was xenon, a gas that promotes the growth of red blood cells that boost stamina. The gas was added to the World Anti-Doping Agency's (WADA) list of prohibited substances for the 2014 World Cup after several Russian competitors tested positive during the Sochi Winter Olympics.
"We heard some rumours about xenon in Russia, so we decided to test that," Dvorak said. "We just tested the Russian team for that because the substance was unknown in the rest of the world. All tests were negative."
Related: FIFA investigating Russian footballers amid widespread doping claims
Speaking for the first time on the matter since his appointment in February 2016, FIFA boss Gianni Infantino echoed Dvorak's statement that the 2014 tests yielded negative results, and that the same stringent testing was used at Euro 2016.
"These tests are not done in Russia," Infantino said. "It's all done outside Russia in Wada-accredited laboratories and they have given negative results.
"These are the facts that need to be remembered. We have all seen the different reports, we are collecting information, and if there have been any anti-doping violations, measures will be taken," FIFA's ninth president added.
"We always have a zero-tolerance policy for doping."