Furious Bayern Munich players sought out ref Viktor Kassai after defeat to Real Madrid last night.

After the 4-2 loss, which saw Arturo Vidal sent off and Real have one goal allowed despite being offside, it's reported Bayern players angrily sought to confront Kassai in the players' tunnel.

Jose Luis Sánchez, of El Chiringuito, reports Bayern trio Thiago Alcantara, Robert Lewandowski and Vidal went to protest against the match officials after the final whistle.

Things became so heated that police had to intervene and usher the Bayern players away.

Witnesses say they could then hear loudly insults and protests from several Bayern members as they were dragged back into the away locker room.