Robbie Williams is reportedly facing a legal fight with Rod Stewart's stepson Ashley Hamilton over a song on his new album, Rudebox.
Ashley claims the popstar has nicked the tune She's Madonna, which the duo came up with when they worked together in LA, reports the Daily Mirror.
He says Robbie then took the half-finished track to the hit band The Pet Shop Boys to complete. The 31-year-old songwriter, whose mum Alana was Rod's first wife, has apparently hired lawyers Dean & Dean to dispute the case.
"We came up with this idea over coffee one afternoon. Robbie said he had an idea for a song about some girl he used to date, Tania Strecker, and how she was dumped by Guy Richie for Madonna," Ashley is quoted by the paper as saying.
"That was a smiley thing to do, so I said, 'Why don't we make a joke song about it?'
"That's how it started. We worked on the lyrics together at home and at the studio.
"The next thing I know, a producer's ringing me up to say congratulations for getting my song onto Robbie's record. I just said 'I don't know what you are talking about'."
Williams, 32, says he wrote the song after seeing Madonna at the MTV Europe awards last year.
"She's Madonna is a collaboration between Robbie and the Pet Shop Boys," a spokesman said.
"We have not had correspondence from Dean & Dean."