Katy Perry reportedly taunted estranged husband Russell Brand with a picture of a beef burger.

The 'Firework' singer is said to have been so furious with strict vegan Russell, 36, after he allegedly filed for divorce without telling her, that she texted him a photograph of her half-eaten McDonald's Big Mac.

A source explained: ''When Russell and Katy were married he tried to convert her to veganism, but she refused to go along with it.

''He'd try to always cook vegan meals for them when they were both at home. He hated her eating meat, especially when he was around to witness it.

''Then when Russell filed for divorce at Christmas, Katy didn't know it was coming. Although it had been agreed that they would divorce, she was furious that Russell filed without warning her first. She felt embarrassed and betrayed.''

Talking to the Daily Star newspaper, the insider continued: ''So as a childish act of revenge, she had a few drinks with her friends and started texting Russell.

''He was ignoring her, so she did the one thing that she knew would get his attention and annoy him.

''She sent him a picture of a half-eaten Big Mac with the caption 'Mmmmm, tasty'. Russell sent her a four-letter, one-word reply.''

The estranged pair - who tied the knot in an Indian ceremony in October 2010 - have since settled the terms of their split with Russell having waived his right to a percentage of Katy's Fortune. Their divorce is due to become official in June.