The explicit images of the former model - naked and smothered in baby oil - came out in 1988 and have been printed by Britain's The Sun newspaper.
One of the shots shows the animal rights activist - who is currently divorcing former Beatle Sir Paul McCartney - apparently having sex a male co-star.
In other photos, 38-year-old Heather - who has a two-year-old daughter, Beatrice, with Paul - is handcuffed as a man peels off her stockings, while another shows her rubbing baby oil into a muscle-bound hunk.
The pictures were originally featured in German book 'Die Freuden Der Liebe - which translates as 'The Joys Of Love'.