CRANBERRIES singer Dolores O'Riordan has initiated a High Court action against bandmate and songwriting partner Noel Hogan.
The High Court proceedings were lodged last week but no court appearances have been set.
The 'cause of action' in the filing is listed as a "declaration" but no further details are given.
The various parties involved are remaining tight-lipped, as O'Riordan's spokeswoman declined to comment, as did her solicitors, Eversheds.
Guitarist Hogan failed to respond when contacted and has yet to give notice of which solicitor will act for him.
Efforts to determine the cause of the issue between the bandmates were met with a stony silence from the close circle of friends around the band.
The pair, along with Mike Hogan and Fergal Lawler, resurrected The Cranberries in 2009 after almost seven years.
They took their new album 'Roses', their first since 'Wake Up And Smell the Coffee' in 2001, on a 107-date world tour but did not play in Ireland.
A source said the legal proceedings could impact future tours, adding that while the duo wrote songs together "it was just for the band. I wouldn't think they were very close."
Another person close to the band said: "They are very insular, but if that is true, there will be no more touring.
"It (the Cranberries) is a vehicle for making money. If they go down that (legal) route, it is going to put a nail on the head."
The Cranberries were thought to be close to a Thomond Park gig last year, yet it didn't happen.
The band went their separate ways in 2003 after selling in the region of 40 million records worldwide, but Hogan said that he and O'Riordan continued to write songs together.
"We did the reunion tour, we started at the end of 2009, but Dolores and I had been writing for a few years before that, not knowing whether it would be a Cranberries album or what it would be," he said in 2012.