The truth is out there - and it's very saucy!

X-Files fans who always dreamed of Agents Mulder and Scully getting sexy on the cult sci-fi show and in movie spin-offs are set for a real treat thanks to porn firm New Sensation.

The two creepy crimesolvers, played by David Duchovny and Gillian Anderson on TV and the big screen, will feature in new adult film The X-Files - A Dark XXX Parody.

New Sensations bosses are keeping the details and casting of the new film under lock and key - just like an X-Files mystery - but one source tells WENN the adult star cast as Dana Scully is the "spitting image" of actress Anderson.

The insider says, "Fans will be amazed. We'll have to dye our Scully's hair - but she's a dead ringer."

Directed by Sam Hain, The X-Files - A Dark Parody features "a mass orgy sex scene with cult members" and "a threesome in an alley".

Filming started on Friday.