with Famous DJ
The DJ in question -- named The Alchemist -- dropped the bombshell in L.A. recently .. telling TMZ, "I'm working on a joint with Vanilli ... Vanilli's making a comeback."
And according to the Alchemist, Vanilli -- real name Fab Morvan -- is bringing his real voice to the recording sessions, adding, it's “real sh*t dude … Alchemist-Vanilli.”
We spoke with Vanilli's rep -- who tells us Fab is DEFINITELY serious about his comeback ... and has recently worked with DJ Tiesto ... one of the biggest DJs in the world.
Hey, if the New Kids on the Block can do it ...