Lady Gaga has reacted to a lawsuit filed against her by a music producer and former boyfriend who claims he was squeezed out of the star's career.

In a lawsuit filed last Wednesday, Rob Fusari alleged to have written some of the stars biggest hits and created her name.

He also said he had a 20 per cent stake in a partnership with the star, Team Love Child LLC, and that he had been denied his full share of royalties.

However, responding to the lawsuit in a court filing on Friday, Lady Gaga's lawyer said the agreement was “unlawful”.

Charles Ortner told the Associated Press that it had been "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”.

He added that Fusari had violated laws that prohibited him from "acting as employment agents without a license and charging Lady Gaga an unlawful fee for their purported services."

Fusari's lawyer, Robert S. Meloni, called the response “ludicrous”.

A spokesperson for Lady Gaga told MTV: "We intend to let this play out in the courtroom, not the media."

(by Jason Gregory)