According to The Irish Mirror, the action is being brought by both Mr Ó Ceallaigh and his company, TAL Management Limited. The company claims that it provided managerial services to the singer for several years for an agreed monthly fee plus commission and expenses.

In 2011, he claims the company was substituted for him under a new agreement and, while it was not executed, it is claimed the parties performed the terms of the new agreement.

In April 2012 he claims that without warning the singer terminated the agreement.

It is also claimed that she was not entitled to do that and he seeks upwards of €500,000 damages for breach of contract, as well as declaration that the management agreement was not validly terminated.

Mr Ó Cealliagh also claims he was defamed by the singer in an open letter published on her website and on a fan's website in 2012, in reply to a newspaper article that referred to the ending of their commercial relationship.

The singer denies she ever had any agreement with TAL or Mr Ó Ceallaigh as alleged or that he and the company are entitled to damages.

She also denies his claims that she defamed him in the letter as alleged.