A report has claimed that a France player may have benefited from the use of a stimulant during the Euro 2016 semi-final victory over Germany.
However, German publication Bild has now published photos which were allegedly taken in the France changing room showing an empty pack of stimulant Guronsan.
Despite the tablet not featuring on the World Anti-Doping Agency's list of prohibited substances, doping expert Fritz Sorgel told the newspaper that it may have handed the hosts an unfair advantage on the night.
"According to the Anti-Doping Code of WADA, any effort to gain advantages over competitors other than through the power of the body is considered doping," he said.
"Guronsan, for me, is therefore doping. Performance can be increased in sport with caffeine. It's been proven. It also increases the cognitive abilities, which means the speed of response."
France had won both previous major tournament finals played on home soil before falling to Portugal last Sunday.