This process involved detectives from the Rotorua CIB, fire investigators, Search & Rescue volunteers, and disaster victim identification experts from Police Search and Rescue.
The investigation deemed this to be a tragic accident, with a candle or gas cooker suspected to have set the hut on fire while the two men slept.
At the conclusion of the investigation the officer in charge of the body recovery and investigation, Detective Senior Sergeant John Wilson, was so moved by the tragedy that he resolved to erect a memorial at the site.
This was done on behalf of Mr Tsuchida's family in Japan, in consultation with the Japanese Consulate in Auckland.
In September 2008 this memorial was erected by Detective Senior Sergeant Wilson and Senior Constable Rob Hutchins from the Murupara Police, near the site of the tragedy.
"I thought that would have been the end of it," says Mr Wilson.
"But then in October last year I heard from Honoka Tsuchida, Katsuya's daughter, who had only been a child when her father died.
"She told me she one day wanted to travel to New Zealand to visit the site where her father had passed away.
"So on Boxing day, nine years to the day after her dads body had been found, Honoka Tsuchida and other members of her family from Japan, met with me in Rotorua after travelling to New Zealand.
"After talking the family through what Police believed had happened to her Dad and his fishing guide we flew from Murupara to the Waiau River where the family spent some time at the memorial.
"It was a very special moment and I feel privileged to have been there and been able to help this family get more of an understanding of what happened to Katsuya," Mr Wilson said.
Honoka Tsuchida, Katsuya's daughter, says this has been an amazing trip for her.
"It was a precious experience that I could finally visit the place where my father died and meet Mr John Wilson who helped and supported us for a long time.
"Thank you New Zealand Police for the incredible opportunity."
