FIFA has closed a doping investigation into all of the Russian soccer players expected to compete in the World Cup next month after finding “insufficient evidence” of wrongdoing.

FIFA, world soccer’s governing body, had opened its investigation after the publication in December of an exhaustive report on doping in Russian sports. The report, the result of an investigation by the Canadian lawyer Richard McLaren and published by the World Anti-Doping Agency, laid out mountainous evidence that for years Russian officials orchestrated a doping program at the Olympics and other competitions that involved or benefited 1,000 athletes in 30 sports, including soccer.

McLaren’s report led to the suspensions of dozens of Russian athletes and to the formal banishment of the Russian team from the Pyeongchang Olympics in February.

FIFA said Tuesday that its investigation had prioritized “high-level players against whom a suspicion had been raised, in particular those who might participate in the 2018 FIFA World Cup in Russia.” Russia has announced a provisional roster of 28 players and seven reserves for the tournament, which begins June 14 in Moscow.