FIFA is investigating allegations that footballers were among the Russian athletes who were involved in a state-sponsored doping scheme.
The governing body would not confirm reports that the 23 members of Russia’s squad at the 2014 World Cup were among those being investigated.
It however said the entire squad underwent FIFA-controlled pre-competition and post-match doping tests, which were all negative.
A report by Canadian sports lawyer Richard McLaren in December said more than 1,000 Russian athletes competing in summer, winter and Paralympic sport were involved in or benefited from an institutional conspiracy to conceal positive doping tests.
The report, commissioned by the World Anti-Doping Agency (WADA) said that more than 30 sports, including football, were involved.
