Rapper Jay Z has been named a defendant in a $600 million (GBP375 million) trademark lawsuit over the Brooklyn Nets basketball team's name.

Businessman Dr. Francois de Cassagnol claims he trademarked the Nets name before the team left New Jersey and moved to Brooklyn, New York.

In court papers filed on 9 December (13), de Cassagnol alleged officials for the National Basketball Association (NBA), Jay Z and developer Bruce Ratner "fraudulently conspired" to use "loopholes" in the U.S. Patent Office so they could trademark the term, according to RadarOnline.com.

De Cassagnol reportedly filed the trademark application in 2012 for The Brooklyn Nets Entertainment Logo, and he claims he was assured by NBA officials there would be no conflict when Jay Z's team moved to New York.

The businessman previously appealed to the Patent Office concerning the matter, but officials on the review board determined he filed his paperwork too late, and that "none of the described uses" of the trademark were enough to overrule the NBA's application.

Now, de Cassagnol is asking a judge to bar officials at the NBA and other associated parties from using the term.

The 99 Problems hitmaker sold his share of the Brooklyn Nets team to coach Jason Kidd last year (13), after opening his own sports agency firm.

He still owns a share of the Barclays Center, the arena where the Brooklyn Nets play their home games.