Several Spartak Moscow fans have claimed police in the World Cup 2018 host city of Kazan refused to allow female fans into the stadium for Friday's match against Rubin Kazan unless they stripped for a search.
In a blogpost which has gone viral among Russian internet users, fan Ekaterina Stepanova says the searches, carried out by male police officers, constituted "humiliation."
Female fans were singled out and "required to strip, and that includes being demanded to remove their underwear" for a search lasting up to 10 minutes, she added.
One female fan told local media she left the stadium rather than submit to the searches, while Stepanova said she refused to strip but was made to wait an hour and a half before being allowed in.
The league's safety director Alexander Meitin blasted the "rough treatment" in comments to the R-Sport agency, adding that the league and Spartak had submitted formal complaints.
Kazan police say all searches at the game were legal and that only fans suspected of carrying contraband were searched.
Spartak fans used smoke bombs during the game, the first Premier League fixture of the season. Spartak won 4-0.
Police are present in force at all major football matches in Russia, with as many as 3,000 officers sometimes on duty at a stadium.
The Russian Premier League has attempted to replace them with trained stewards employed by the clubs, although the police have resisted any change.
Kazan is one of 11 host cities for the 2018 World Cup in Russia, when matches will be held at the Kazan Arena.
The new stadium will host its first football match August 17, as well as next year's world aquatics championships.