On Monday, they said the man with a lengthy criminal past was at the centre of a missing person investigation and on Tuesday they upgraded it to a homicide inquiry.
Mr Hansen's cousin Sandy Maniapoto said he last saw him four weeks ago.
"I went around to his house and cooked him steak and eggs," Mr Maniapoto said.
"We arranged that he would call me, because we were going to work on one of his trucks."
But Mr Hansen did not call and after a couple of weeks Mr Maniapoto began to get worried. "Then I heard he was working on a truck in Palmerston North."
Mrs Maniapoto recalled the day she was working in Lower Hutt and visiting the Epuni boys' home for children in trouble when a little boy put his hand on her shoulder. She turned around and saw her nephew.
"I got such a shock ... I went to court and brought him home."
Mrs Maniapoto said her nephew was very loyal to all his family, adding that it was sometimes to the point of stupidity.
She has four sons but says young Whitu was loved as much as her own children.
Mr Maniapoto said: "He's my cousin but I love him like a brother.
"He was in jail for three-quarters of his life. The gangs wanted him to join them but he rode alone. He was old school and always believed that your word was your bond."
Mr Maniapoto tried to get his cousin away from crime and into sport - "he was a really good league player".
In jail, Mr Hansen would look after other guys. "He was afraid of no one and would stand up to anyone, even though he was not a big guy. He was an entrepreneur and would pick cigarette butts off the floor and make them into new cigarettes and sell them, one for $5. That's how he made his money."
Mrs Maniapoto always said her nephew was an entrepreneur and wanted him to use that on the outside, but not in an illegal way.
When he came out of prison he could not get work so he resorted to other ways of making money. "He was not a nark," Mr Maniapoto said. "You don't spend three-quarters of your life in jail if you're a nark."
They spoke of a tender man beneath, who loved his family and his uncle, Mrs Maniapoto's late husband Ike, who became his father figure. When he came to visit his auntie, he would go into the lounge and sit and speak to his uncle's picture on the wall. But his life behind bars meant he was always on the edge, Mrs Maniapoto said.
Mr Hansen is a father and a grandfather.
"In the past he would tidy up his loose ends before he went back to jail and then hand himself in," Mrs Maniapoto said. "He was thoughtful and cared more about others, but he needed to think more about himself." The family hope he will come home but, as each day passes, that hope fades.
