The Vines have been forced to cancel a string of tour dates due to their singer's ongoing battle with Asperger's Syndrome.

“Craig Nicholls’ mental condition has deteriorated extremely rapidly over the past month to the point where he requires immediate help over an extended period of time,” the band said in a statement.

Nicholls was diagnosed with the disease in 2004 but successfully returned to the stage two years ago.

The affected dates include a number of Australian festival appearances - Homebake, Pyramid Rock and Big Day Out – and the group's forthcoming Japanese world tour.

"On behalf of The Vines we would like to extend our sincerest apologies to those of you who have bought tickets to see us perform and will not get to do so,” band member Hamish Rosser said.

“We are all absolutely devastated that we've been forced to cancel all upcoming shows as there's nothing we love more than playing on stage before an enthusiastic audience.

"We ask for your understanding in this situation”

A spokesperson for the Big Day Out festival said they were “deeply saddened” by the news and extended their support to Nicholls' family.

(by Jason Gregory)