U2 star Adam Clayton is suing the man behind the group's finances for alleged negligence.
The Irish bassist has filed papers against Gaby Smyth and two other accountants in Dublin's High Court.
It is not clear what sparked the new legal spat, but Britain's Daily Mail newspaper has linked the action to Clayton's recent High Court case against a former housekeeper, who allegedly defrauded him of up to $2.2 million (£1.4 million).
A source tells the publication, "It would be unwise to assume that this case relates to the case against his housekeeper, but that's not to say it has nothing to do with her.
Smyth was the mastermind behind the band's controversial decision to move its publishing company to Holland in 2007 to save money - royalties it would have otherwise paid under Irish tax law.