We previously reported that Scottish band Franz Ferdinand had been approached by Warner Bros. to write songs and appear in the next Harry Potter movie, but now according to British tabloid The Mirror Franz Ferdinand have decided to pull out of the Harry Potter and the Goblet of Fire movie.
The report states that band tension as the deciding factor with some members coming to blows after a recent concert in France. But according to a band spokesman the reason for their pulling out of the movie is scheduling:
There was a bit of a row, that's normal. They can't make the film because of scheduling."
UPDATE: Thanks to Jonas from hp-fans.de in Germany for a translation of an article from Germany's MTV that mentions that the roles of the Weird sisters will now be played by Radiohead members John Greenwood & Jarvis Cocker:
Franz Ferdinand cancelled their roles in the upcoming Harry Potter movie Harry Potter and the Goblet of Fire. Alex, Bob, Paul and Nick were planned to play a guest role as a band named the 'Wyrd Witches'. British newspaper Mirror reports that the tensions in the band, which caused arguments between Alex and Nick this week, were the cause for this decision. But a spokesperson of the band demented: 'There has been a little argument, that's normal. They can't act in the movie because they don't have the time for that.' The role of the 'Wyrd Witches' will now be played by Radiohead members Jonny Greenwood and Jarvis Cocker."
Treat all of this as a rumor until it is denied or confirmed by Warner Brothers.