Kahn, the Bayern goalkeeper and captain, and Lucio, the club's Brazilian centre-back, have been summoned to a UEFA disciplinary hearing on Thursday for improper conduct during the control on March 7.

Kahn has sent a written apology to UEFA and he explained in an interview published on the Bayern website (www.fcbayern.de) on Tuesday that he lost his temper during the control.

"It was two hours before I could give a sample and then when I brought the beaker to the doctor he said I'd have to do it again because he wasn't present for it," Kahn said. "I was tired, annoyed and at the end of my tether.

"I'd like to apologise to the doctor. It shouldn't have happened."

Bayern's 2-1 win over Real in the second leg was enough to take them through to a quarter-final against AC Milan and Kahn said he did not expect to be banned.

"I've played over 100 Champions League matches and I've done nothing to be reproached for," the former Germany international said. "I assume I'll be playing."