Dead Producer Vs Earth, Wind & Fire Star

The man at the center of the controversy is Charles Stepney -- who produced a bunch of EWF hits from 1974 until his death in 1976 ... including Shining Star, Mighty Mighty, Devotion and Sing a Song.

But according to a new lawsuit, obtained by TMZ ... Stepney's children claim they recently discovered their dad NEVER got any royalty checks for his producer work on the EWF hits ... even while he was alive.

Now, they want Maurice ... along with Sony Music Holdings, Inc ... to fork over a HUGE check for all of the royalties they claim they deserve ... dating all the way back to 1974.