The newly-divorced comedian shocked a live audience during the filming of his American show by saying the singer gave him "ass-ache".

The 37-year-old star was at Solar Studios in Los Angeles on Sunday filming this week's instalment of his chat show BrandX for network FX.

While he refused to go into depth about his legal union to the 27-year-old singer after they announced their split in December, he had now admitted that she was irritating.

An audience member told the Daily Star newspaper: "Russell was bantering with the audience, in particular a couple called Curtis and Katy. He got onto the subject of their sex life. Katy was giving as good as she got.

"Then, all of a sudden Russell shouted: 'Anyway, enough of you. I've had enough ass-ache from people called Katy in the last year.'

The source continued: "It was obvious he meant Katy Perry. The whole room gasped. I think it took a couple of seconds for what he'd said to sink in.

"He then laughed and shouted: 'Oh no, there might be a journalist in the room.' He shrugged his shoulders and murmured: 'Oh well,' before moving onto his next subject."