50 Cent & Dr. Dre Sued: They Straight Pimped 'P.I.M.P.' From Me!

50 Cent needs to pass some of his pimp juice to a producer who says "P.I.M.P." was jacked from him ... and he's looking for compensation.

Brandon Parrott says he sent 10 tracks to Dr. Dre in 2001 ... in hopes one of Dre's artists -- like Eminem -- would record his music. Cut to 2003, when Parrott says he got a call from a producer for Dre's company, Aftermath Entertainment.

He says the producer admitted Parrott's track, "BAMBA" was used in "P.I.M.P." -- and was included on 50's huge debut album, "Get Rich or Die Tryin'". Parrott says the producer pleaded ignorance -- that he had no idea "BAMBA" was going to end up on the final edit.

In other words: It was an honest mistake.

Parrott says he signed a settlement deal based on that story -- but he's recently heard interviews where it's now clear to him it was no mistake. He feels 50 and Aftermath took advantage of him.

Parrott's going after both parties for a cut of that "P.I.M.P." dough.