Cocker unhappy over 'Harry Potter' songs
The singer appears alongside Radiohead stars Phil Selway and Jonny Greenwood as musicians The Weird Sisters in Harry Potter and the Goblet of Fire, however his plans to release the music written for the film have been blocked by Rowling.
"Jarvis was really disappointed as he thought the songs were very good and wanted to release an album," an insider explained. "He was upset as JK put her foot down and wouldn't allow it. She thought a group releasing CDs separately would confuse children."
Warner Bros are also currently involved in a dispute with a Canadian group called The Wyrd Sisters, who are unhappy that their name is being used in the film.