Rapper 50 Cent has asked a judge to dismiss a copyright infringement case against him - because the plaintiff doesn't own the song he's accused of sampling.

Robert Poindexter has sued 50, claiming the rap star used a portion of his track Love Gonna Pack Up and Walk Out on new tune Redrum without permission - and now the In Da Club hitmaker is firing back.

In court papers obtained by Tmz.com, 50 insists Poindexter doesn't even own the rights to the Persuaders song and he maintains he never violated any copyright laws.

He claims Poindexter signed the rights to the song over to Warner Music Group and therefore he can't sue. 50 Cent is asking a judge to dismiss the case.