Marvin Gaye's son is the latest guy to claim "Empire" was his brainchild ... he's about to sue over it, and remember, the guy's got a good track record in court.
We've learned Marvin Gaye III claims he registered a treatment on a show called "Diamonds & Ballads" (aka "Those Sons of Riches!") with the Writers Guild of America back in 2010.
Gaye says the treatment describes a family in the music business -- "a music based 'black' and 'hip' version of 'Dynasty' ... with a little 'Sopranos.'"
We're told Gaye shopped the treatment around to TV execs and said it was loosely based on the lives of his legendary family and the Berry Gordy family.