The Los Angeles County Sherriff's Department is investigating the death of the girlfriend of Clark Gable's son, authorities said.

Christiane Candice Lange, 41, was found unresponsive after police arrived at the home she shared with John Clark Gable in Malibu Wednesday.

Authorities told ABC News' Los Angeles affiliate KABC that Lange told Gable she wasn't feeling well before going to bed Tuesday night. When Gable checked on her about 10 a.m. the next day, he was unable to rouse her.

The Los Angeles County Sheriff's office told ABC News the cause of death is unknown and the coroner is investigating.

Ed Winter, assistant chief of investigation at the Los Angeles County Coroner's Office, said that foul play is not suspected, but that the department is on a security hold and cannot release any further details.

According to Lange's website she was a make-up artist and hairdresser who specialized in professional makeovers. The website also says she trained with celebrity makeup artist Alexis Vogel, who gave Pamela Anderson her famous look.

John Clark Gable is 51 according to IMDB. He is the only son of the late Hollywood legend and star of "Gone With the Wind," Clark Gable.  He was born shortly after his father died of a heart attack at age 59.