LOS ANGELES (REUTERS) - Detectives are investigating the disappearance of a Hollywood studio executive as a homicide 10 months after he vanished under suspicious circumstances, and are seeking the public's help in solving the high-profile case, authorities said on Thursday.

Gavin Smith, a 57-year-old film distribution executive for 20th Century Fox, was last seen on the night of May 1, 2012, driving in his black Mercedes Benz away from a friend's house in the community of Oak Park, north-west of Los Angeles.

The Los Angeles (LA) County Sheriff's Department said in a statement that the Mercedes had been found in late February in a storage facility in Simi Valley, about 32.2km away by freeway.

The storage facility has been linked to a man currently being held at a LA County jail on an unrelated narcotics conviction, according to the sheriff's department.

That man, John Creech, has not been named as a suspect in Smith's disappearance.

"Based on the vehicle's condition and information developed from persons cooperating in the investigation, homicide detectives are now investigating this case as a homicide," the sheriff's department said.

"Gavin's body has not been recovered," it said.

Detectives were looking for assistance from the public in identifying anyone who may have been involved in moving the Mercedes from the Porter Ranch section of LA to the storage facility about a week after Smith went missing.

The sheriff's department did not say how they believe the Mercedes came to be in Porter Ranch, about 40 minutes by car from Oak Park.

When Smith drove away from his friend's home, wearing purple athletic pants belonging to one of his sons, he left behind his cellphone charger, shaving kit and other personal items, authorities say.

The disappearance of Smith, also known for playing on UCLA's 1975 national championship basketball team under legendary coach John Wooden, made local headlines and family members pleaded for help from the public in finding him.

His son Evan Smith, a forward for the University of Southern California basketball team, took to Twitter to get the word out, tweeting such messages as "I will not stop until I find my father."