On Jan. 4, two joggers discovered the naked body of Anneka Vasta on a beach in Camp Pendleton, Calif., a Marine Corps base north of San Diego. The woman was so slim and youthful that she was initially thought to be a teenager. But it turned out to be  the body of a 58-year-old woman.

Vasta was later identified as a former model and Hollywood B-list actress, who posed nude for Penthouse magazine more than three decades ago. The former model, also known as Anneka Di Lorenzo, was Penthouse's Pet of the Year in 1975.

According to an autopsy, the body was found with a broken neck and back. The cause of death was listed as drowning.

Mystery still surrounds the death of the woman who once aspired to be the sexiest woman in the world. To help unravel that mystery, officials from the Navy Criminal Investigative Service are asking for a help from the local population.

Authorities investigating the case are interested in how Vasta actually got to the remote beach 35 miles north of San Diego and are also looking for evidence confirming a possible suicide.

Susan Thoreson, Vasta's sister, said Vasta was divorced and in between jobs. She was last seen on Jan. 2, when she drove away from her Los Angeles home. Vasta's sister also told the Daily Mail her sister began showing signs of mental problems about six or eight years ago.

Authorities are asking anyone who may have seen a 2001 Mazda 626 sedan along Interstate 5. Vasta's car was found parked at a scenic coastal overlook, atop a 60-foot bluff above a sandy beach, along with her purse and mobile phone. Authorities are also trying to determine whether the incident was a suicide, an accident or a murder. According to investigators, she couldn't have jumped from the bluffs; the tide was too low at the location for the body to hit the rocks.

The most important question surrounds the mystery is that how she got from her vehicle to the water. We are aware that she died in water due to some circumstances but don't know how, said Special Agent Rachel McGranaghan, one of two naval investigators leading the case.

In 1990, Vasta sued and won $4 million from ex-boyfriend and Penthouse publisher Bob Guccione. She alleged that he had sexually harassed her. Vasta, who went on to become a nursing assistant, also had a history of mental health problems, including paranoia; she was on medication for her problems but an autopsy showed no drugs in her body.

Vasta left Los Angeles on Jan. 2 and rented a room at a Motel 6. However, there is no proof that she actually used the room. There were signs of struggle inside her car and, apart from her purse and mobile phone, a leopard-print blouse and a sports bra with blood stains were found wrapped in a plastic bag inside the car.

Additionally, a steak knife with Vasta's blood was found on the passenger floorboard and slashes were found on Vasta's wrist. However, the latter were not deep enough to kill her.

Her mental problems aside, Vasta's family refuses to consider suicide as an explanation.