Wellington Police and the family of Kaye Stewart will announce a reward of up to $50,000 tomorrow for information which leads to Mrs Stewart's body or a conviction relating to her disappearance.
Mrs Stewart, who was 62 when she went missing, was last seen walking in Rimutaka Forest Park on Monday 13 June 2005.
It has been almost two years since her disappearance, giving rise to a strongly-held belief that she has been the victim of foul play and is now dead, says Detective Senior Sergeant Ross Levy of Lower Hutt Police.
"Given that there were two intense physical searches at the time, a huge number of family and volunteer searches since, and that almost two years have passed with public activity and weather changes in the park, it is surprising that no evidence relating to her disappearance has been discovered."
The reward includes consideration of an indemnity against prosecution for any accomplice, who is not a principal offender responsible for her disappearance, who is the first person to come forward with information or evidence.
The offer remains in force until 13 July 2007, one month after the second anniversary of Mrs Stewart's disappearance.
The family has arranged for leaflets about the reward to be delivered to all homes in Wainuiomata.
Mrs Stewart went to the Catchpool part of the Rimutaka Forest Park at about 10.30am on the morning of Monday 13 June 2005. She was lightly clad and planned a short walk before meeting family in Wainuiomata at 12.30pm. When she failed to arrive, they went to the park, found her car locked and, after a check of nearby tracks, contacted the Police.
Police inquiries established that she had spoken to a Department of Conservation staff member in the Rimutaka Forest Park visitor centre at about 10.30am to decide on a suitable one hour walk.
The last reported sighting of her was at about 1.05pm when it is believed she spoke to a second DoC worker at the department's workshop on the Wainuiomata Coast Road, about 2km from her car. He gave her directions for how to find the car park, but she did not return to her car.
"If she had followed the directions given to her, the tracks and roadway were well-marked and she should have been able to find her way back to her car," says Detective Senior Sergeant Levy.
A four-day search involving over 40 searchers, helicopters, heat seeking camera equipment, search dogs and police divers was launched the day she went missing.
Conditions were cold, wet and windy giving searchers little hope that Mrs Stewart would have survived in the open in the light clothing she was wearing.
Searchers combed trails, tracks, bush, logging areas, roadside verges, streams and the Wainuiomata River. Aerial sweeps were made out to the Wainuiomata coast.
Nearly two weeks later on 28-30 June, a second intense search was launched. DoC closed the park to the public and up to 80 people including police and volunteer search and rescue personnel, police divers, the police specialist search group and 20 army personnel were involved.
In the meantime, detectives and recruits from the Police College had canvassed homes on the Wainuiomata Coast Road to make residents aware of her disappearance and ask them to check their properties.
"In the absence of any clues as to where she was or where she may have gone, it was no longer feasible to continue the search," says Detective Senior Sergeant Levy.
"Her disappearance remains a mystery. Kaye was in good health and good spirits."
Before retiring she had been a physiotherapist treating many top sportspeople including former All Blacks.
Mrs Stewart's unexplained disappearance has had a huge toll on her husband and daughters.
"We really miss mum, dad misses her, and our children don't understand where Gran has gone," says daughter Jane Galanakis. "We want to lay her to rest."
Description of Kaye Stewart
Mrs Stewart was 1.75m tall, medium build with greying light brown hair. On the day she went missing she was wearing a light nylon dark blue jacket, anorak style, dark tracksuit pants, a pink ribbed jersey and white sandshoes.
Driver of quad bike still sought
Police still want to identify the driver of a quad bike, possibly red and maybe towing a trailer, seen on the Forest Park Road at about 1.50pm on the day Mrs Stewart went missing.