Misty Upham's body was believed found in Auburn, Wash., on Thursday.
The 32-year-old actress was reported missing October 6, a day after police responded to her apartment for a suicide call. Police spokesman Steve Stocker said the body was discovered at the base of a 150-foot embankment, with Upham's purse and identification near by. The medical examiner will determine a positive identification of the body.
Upham's father, Charles, asserted he didn't believe his daughter to be suicidal in a Facebook post Sunday, but admitted the actress struggled with mental illness.
"As her father I do not fear she committed suicide," he wrote. "I feel that she has been hurt by accident or someone has put her in harms way."
"Misty has suffered from mental illness most of her life," he revealed. "With the help of her medical team and family support she is able to manage it well... Misty believes that suicide is a sin and in her darker moments she would tell me, 'Dad, I would never take my own life.'"
Upham is best known for her role as Johnna Monevata in August: Osage County, and also appeared in Frozen River, Django Unchained and on HBO series Big Love.