Bayern Munich manager Jupp Heynckes has refused to comment on reports in the German media that duo wide duo Franck Ribery and Arjen Robben were involved in a half-time bust-up in the Champions League game against Real Madrid on Tuesday.

The pair are reported to have fallen out over who was going to take a free kick against the La Liga leaders.

Sport Bild magazine claims Frenchman Ribery punched Dutch teammate Robben in the face and pictures appeared after the game of Robben with a cut under his right eye.

Heynckes, however, has decided to keep quiet on the speculation.

"There are taboo zones within a football team," he is quoted as saying by Bild.

"Given the huge media presence, that is also necessary. I believe that internal matters must remain internal, whether that is here at our training ground or in the dressing room.

"Everything else is speculation and I will not respond to that."

Munich take a 2-1 lead to the Bernabeu on Wednesday.