Lady GaGa is hitting back at the music producer that is suing her after claims that he launched her career.

GaGa is being sued for £20.3 million.

In court papers that were made public GaGa’s lawyer has said that the agreement which is at the heart of the suit is in fact “unlawful”.

The suit was filed on Wednesday in Manhattan by song writer and music producer Rob Fusari.

Fusari claims that his former girlfriend (Lady GaGa) and his protégé left him after her career took off.

The lawsuit claims songs such as Paparazzi and Beautiful, Dirty, Rich were co written.

Fusari also claims that he helped her to come up with the stage name Lady GaGa and helped her to get her record deal.

The lawsuit says that Fusari and Lady GaGa had a romantic relationship which became a business partnership in May 2006, in which time the pair created a joint venture called Team Love Child that was meant to promote Lady GaGa’s career. Fusari claims that his share was 20%.

In response to these claims Lady GaGa’s lawyer wrote in his response that the arrangement between the pair was “structured in such a way as to mask its true purpose – to provide to the defendants unlawful compensation for their services as unlicensed employment agents”.

Lady GaGa’s lawyer also wrote that Fusari and the company he had in fact violated statutes which forbids them from “acting as employment agents without a licence and charging Lady Gaga an unlawful fee for their purported services”.

Fusari’s lawyer called this claim “ludicrous”.

“Fusari is a PARTNER in the Team Love LLC with Gaga and her father (through their company Mermaid),” Fusari’s lawyer wrote in an email. “Rob was no more of an ‘agent’ for her than she is a Roman Catholic nun.”