Frusciante has apparently been replaced by Josh Klinghoffer, who is understood to have already been rehearsing with the band.

A source told MusicRadar that Frusciante quit in order to embark on other ventures.

"Mentally, John checked out a long time ago,” the source said.

“He's interested in doing his own thing, his own albums - the whole big rock band machinery just doesn't appeal to him anymore."

The unconfirmed reports come just months after it was revealed that Red Hot Chili Peppers had begun work on their next album.

The follow-up to 2006's 'Stadium Arcadium' is due to be released next autumn.

(by Jason Gregory)