A mystery woman with an Australian accent and stage-three cancer says she has no idea who she is, where she's from or how she wound up lost and penniless in California.

Authorities first encountered the woman on Feb. 1, when firefighters responded to a call about a dishevelled woman in Carlsbad, a town north of San Diego. The woman was barely conscious, with no purse or identification on her. She also did not know her own name or where she lived.

The woman has been diagnosed with amnesia and stage-three ovarian cancer, which has her eager to reconnect with her family before her condition worsens.

Several law enforcement agencies from around the world are attempting to identify her. She has also started conducting media interviews with the hope that someone will recognize her and help her find her family.

"I just feel like there's a thick fog over my memory," she told NBC News in California. "I can't remember anything."

She says she has vivid dreams of Australia, and of living in a contemporary home in Hawaii. She adds that there is one man who repeatedly appears in her dreams, but she doesn't know who he is.

"I have this dream of this bloke in my dreams all the time," she said. "I don't know if I was married to him... I think so."

The Caucasian woman appears to be in her fifties, with white hair and brown eyes. She stands 1.7 metres tall and weighs 91 kilograms, authorities say.

"I'm hoping that someone sees me… and my family immediately says, 'There she is!'" the woman said.

"Sam" has since been identified by her sisters .