What happened to a mother of five who vanished in north Queensland in 2005 remains a mystery, although a coroner has ruled she was likely murdered.

A mother of five who vanished in Queensland’s far north in 2005 was likely murdered, but who killed her and where her body lies remains a mystery, a coroner has ruled.

Kathleen O’Shea was visiting the Atherton Tablelands, inland from Cairns, for the birth of her first grandchild when she disappeared on December 29, 2005.

No one has been charged over the 44-year-old’s death.

Ms O’Shea was dropped off on a street in Atherton on the day she died by her son Alan, and was last seen with two men buying beer from a local hotel.

Northern Coroner Jane Bentley ruled on Thursday, following an inquest into the disappearance, that Ms O’Shea was likely murdered.

“The cause of her death cannot be determined, but it is most likely that an unknown person or persons caused her death and disposed of her body,” she said.

Ms O’Shea likely met the person or persons at the Atherton Hotel or soon after she left there.

On Wednesday, counsel assisting the coroner, Stephanie Williams, said it was possible her son, a man who is a convicted rapist, or a person unknown killed Ms O’Shea, who had been visiting from Melbourne.

However, Ms Williams said there was no evidence linking the possible suspects.

Alan reported his mother missing two weeks after she disappeared, and a witness told the inquest he had confessed to killing her.

However, Ms Bentley said it was unclear whether this was a confession or whether he felt somehow responsible for his mother’s disappearance.

A convicted rapist who had been living in the Atherton Tablelands in 2005 gave evidence at the inquest.

The man, who cannot be named for legal reasons, is serving a prison sentence for abducting and repeatedly raping a woman in 2007.

He is also a person of interest in an interstate missing-person case.

Ms Bentley said it was possible, although unlikely, that Ms O’Shea had died from an accidental drug overdose and someone had disposed of her body.

No one was named as a suspect by the Coroner and the inquest was closed.