Russell Brand on Jonathan Ross swearing incident on Radio Two.
Russell Brand has apologised for offending Fawlty Towers actor Andrew Sachs during a prank on his Saturday night BBC Radio 2 programme.
The actor's agent said Sachs was "very upset" after Brand and guest Jonathan Ross left lewd messages on his answer phone which were aired on 18 October.
Brand said on his latest show "you musn't swear on someone's answer phone", but added it was "funny".
The BBC said they were "not aware of receiving a complaint from Mr Sachs".
A spokeswoman said the programme received two complaints unrelated to the phone calls, while they have had further complaints since the details of the stunt were publicised.
The 78-year-old actor's agent, Meg Pool, has written a letter to Radio 2 controller Lesley Douglas asking for an unreserved apology.
Sachs, who played Manuel in Fawlty Towers, was expected to be a guest on the programme, but was unable to appear due to unforeseen circumstances.
Ms Pool told BBC News that he had passed on his mobile phone number to Brand's production team "in good faith", which the presenter used to contact him during the show.
Andrew Sachs was unable to answer Brand's calls
Both Brand and Ross made obscene comments about Sachs' 23-year-old granddaughter on a series of messages which they left on the actor's voicemail during the segment.
Talk show host and Radio 2 presenter Ross has so far declined to comment on the incident.
Ms Pool added that the actor did not hear the programme, but listened to a recording and was "offended very much indeed" by its content.
Earlier this year, Brand apologised for making a hoax call to the police during a stage show in Northampton.
He rang a police line in front of an audience and said he may have spotted a man who was responsible for a series of assaults.
Brand later said he was "devastated by the possibility" that he "may have offended vulnerable people".
The 33-year-old star, who hosted the MTV Music Awards in Los Angeles last month, has been a regular presenter on Radio 2 for almost two years.