Perry230.jpgKaty Perry is suing the Australian magazine that claimed she had an affair with her record producer, Benny Bianco.

NW said that Perry, 26, cheated on her hubby Russell Brand, 35, with the music man after she and Brand had married.

The singer filed the claim today in Melbourne, Austalia after landing there to perform for her world tour.

NW wrote the article last month, saying that Perry and Bianco had an "intimate relationship" and that her marriage was now in trouble.

See how much Katy could stand to win in court after the jump!