Iraena Asher likely to have drowned

The inquest into the fate of Iraena Asher has heard it's most likely she drowned at Piha Beach.

The 25-year-old trainee teacher and model was last seen on October 11, 2004, on Auckland's west coast.

The court's heard she suffered from bipolar disorder from the age of 15 and was required to take medication daily.

A man who was with Iraena Asher the night she went missing says she was acting unusually.

Jesse Pragert says there were several people at his house in Piha the night she disappeared, and Ms Asher was drinking, smoking cannabis and dancing around naked.

"She was quite zombie-like, like real vacant - you couldn't actually talk to her ... you couldn't have a proper conversation with her, and extreme highs and extreme lows."

The boyfriend of Iraena Asher says her behaviour on the day she disappeared caused him concern.

The man, who has name suppression, says they were drinking and smoking cannabis the day she went missing.

"I did think it was strange that she went off in the rain, down to the beach - it's a three or four k' walk and return back covered in mud - been swimming in the lagoon in the middle of winter sort of thing."

A woman also with Iraena Asher the night she disappeared doesn't believe she was being pressured for sex.

She left a house she’d been at and called 111 asking for help saying she felt scared and was being pressured, but police sent a taxi to Onehunga.

Coroner Peter Ryan has questioned the woman if anything happened to make her feel like that.

She replied that she was not aware of any incident that made Iraena feel scared or unsafe.

Later that night Iraena Asher left the house again, but never returned.

The former boyfriend of Iraena Asher says she told him she was on edge just weeks before she went missing.

Julian Dyson and Iraena Asher had been together four years, but broke up a week before she disappeared.

"The weekend before we broke up, she went missing for a couple of days. I was worried about her, I called the hospital asking admissions if anyone by her name had been admitted," Mr Dyson says.

He says when she returned she told him she'd been with staying with his flatmate's brother, and after that they broke up.

The officer in charge of the investigation into her disappearance, Senior Sergeant John Sutton, says while it's possible she may have walked into the bush, or been the victim of foul play, the most probable explanation is that she drowned because she was in a manic state.

Photo: Iraena Asher (supplied)