Anneka Vasta, 58, made her name with a series of racy shoots for Penthouse, who's founder Bob Guccione she she dated.
She also starred in his infamous multi-million dollar, soft porn flick, Caligula but later sued him for $4million after he made her have sex with two of his business associates.
The woman born Marjorie Lee Thoreson, in St Paul, MN, was discovered by joggers at Camp Pendleton in Jaunary this year.
Now her family and federal investigators are mystified about how Vasta, who became a Los Angeles-area nursing assistant with a grown daughter, ended up drowned on the beach with a broken neck and back.
But federal agents are stumped as to how she got there, although her family maintain she would not have committed suicide.
Special Agent Rachel McGranaghan told the San Diego Tribune: “The main unanswered question that we have is how she got from her vehicle to the water. We know her life ended in the water, in some circumstance, we just don’t know how.”
Her sister Susan Thoreson says it’s possible that her sister, alone or with someone she met, somehow tried to go swimming and was overcome by the cold winter surf.
She told the paper: "I think something happened when Anneka couldn’t maybe fend for herself.”
But, she added, “Here’s my fear. What if there is a perpetrator out there, who is going to do this to someone else’s sister or mother?”