A songwriter and music producer who claims he helped launch Lady Gaga's career filed a $30.5 million lawsuit against the pop superstar, The Associated Press reported Thursday (March 18).

Rob Fusari says he was squeezed out of Gaga's lucrative career after he co-wrote some of her songs, came up with her stage name and helped her get a record deal. Fusari's lawyer hadn't returned MTV News' calls for comment by press time; Gaga's rep also hadn't commented on the suit.

The producer said Gaga is his protégé and former girlfriend, and she ditched him as her career took off. "All business is personal," said the lawsuit, filed Wednesday in Manhattan.

Fusari, who had worked on Will Smith's "Wild, Wild West" and Destiny's Child's "Bootylicious" when he teamed up with the singer back in March 2006, said he persuaded her to trade in her rock music for dance beats.

As they co-wrote songs such as "Paparazzi" and "Beautiful, Dirty, Rich," which would appear on her debut album, The Fame, he transformed Stefani Germanotta into Lady Gaga, a name adapted from Queen's "Radio Ga Ga," the lawsuit claimed.

Lady Gaga told the AP in a 2009 interview that her "realization of Gaga was five years ago, but Gaga's always been who I am."

"I was Gaga from the time that I was 19 through my first record deal," the 23-year-old said of her over-the-top style. "I always dressed like that before people knew me as Lady Gaga. I was always that way. ... I stuck out like a sore thumb."

Per the lawsuit, Lady Gaga and Fusari's relationship turned romantic and then became a business partnership in May 2006, when they created a joint venture called Team Love Child LLC to promote her career. Fusari's share was 20 percent, it said.

Fusari says he introduced Lady Gaga to a record executive who ultimately shepherded her to Universal Music Group's Interscope Records, which released The Fame in 2008. While Fusari has a producing credit on the album, he said he has been denied a 20 percent song-royalties share and 15 percent of merchandising revenue. He acknowledges getting checks for about $611,000 but said that isn't his full share.