Missing Qld woman 'may have been murdered'

A mother-of-five who vanished in far north Queensland in 2005 may have been murdered, an inquest into her disappearance has heard.

However, Kathleen O'Shea's family may never know what happened to her as there's no concrete evidence linking the possible suspects to her disappearance.

On Wednesday, the final day of the inquest, a Cairns court heard the 44-year-old woman may have been murdered by a convicted rapist, a person known to her or someone else.

"Given the lack of evidence it is my submission that Your Honour make an open finding," counsel assisting the Coroner, Stephanie Williams, said.

"[How she died] is a matter that's been unable to be determined."

Ms O'Shea was last seen in Atherton, inland from Cairns, on December 29, 2005, and was reported missing about two weeks later.

She had been visiting the area from Melbourne for the birth of her first grandchild.

Ms Williams said a convicted rapist who had been living in the area may have killed Ms O'Shea who was known to hitchhike.

The man, who gave evidence during the inquest, is also a person of interest in an interstate missing persons case and is serving a prison sentence for abduction and rape.

Ms Williams also said another man, who was known to Ms O'Shea and who witnesses said had admitted to killing her, may have been responsible for her death.

Another possibility was that Ms O'Shea had died of an accidental drug overdose and someone had disposed of her body over fears they may be blamed.

Ms O'Shea's daughter Lily Parmenter told the court she believed her mother had been murdered.

She said evidence, including a vehicle spotted in the area on the day her mother disappeared, pointed to the convicted rapist possibly being responsible.

The other man may have admitted to causing Ms O'Shea's death because of "third party guilt" but hadn't harmed her mother, she said.

Northern Coroner Jane Bentley will hand down her findings on Thursday morning.