The woman says she was repeatedly groped by a man who also tried to open her bra during Schalke's match against Nuremberg at Veltins Arena on Saturday.

Police in Gelsenkirchen said the 22-year-old woman has filed a complaint and they are trying to identify him.

Officers are also investigating the alleged behaviour of the steward.

Police confirmed they had started a criminal investigation after the woman filed a complaint after the game.

Schalke told BBC Sport they were taking the allegations "very seriously".

The club have launched an internal investigation and added: "We are in the process of getting an overview and working in close cooperation with the police."