Body may be missing actress

• NEW: Police say a purse containing Upham's ID was found with the body


• Actress was last seen October 5 and reported missing the next day


• Upham appeared in "August: Osage County" and "Frozen River"

(CNN) -- The body of "August: Osage County" actress Misty Upham is believed to have been found along a river in suburban Seattle, police said Thursday.

The body was found by a member of Upham's family during a search for the actress, according to police in Auburn, Washington. It was found at the bottom of a steep embankment near the White River.

The body has not been officially identified, but a purse containing Upham's ID was found with the remains, police said.

Upham, 32, was last seen October 5 walking from her sister's apartment in Muckleshoot, Washington, according to a statement sent to media outlets by her father, Charles Upham. She was reported missing the following day.

Actress' disappearance baffles family

Her father said she has bipolar disorder and bouts of depression and anxiety, but didn't think she was suicidal.

"The truth is Misty is not stressed over money or career. Her career is going great," he wrote Sunday. "As her father I do not fear she committed suicide. I feel that she has been hurt by accident or someone has put her in harms way."

Upham had small roles in "Django Unchained" and "August: Osage County," and was nominated for an Independent Spirit Award for her performance in 2008's "Frozen River." She's also had roles in the TV series "Big Love" and the TV movie "Skinwalkers."

She was currently shooting a film called "Crawlspace," according to the Internet Movie Database.

CNN's Cheri Mossburg and Lorenza Brascia also contributed to this story.