Mrs Ngahooro's body is understood to be lying in a marae near Taumarunui.
Police this afternoon blocked a private road to the marae and threatened media with trespass notices.
Police national headquarters spokesman Jon Neilson said they had limited legal power to intervene.
"Body snatching is not against the law," Mr Neilson told NZPA.
"Unless there is a valid court order issued to the family either stopping the body from being taken or giving police the right to get one that has been taken there is nothing we can do."
A body cannot legally be owned, police said.
Ms Ngahooro was married to a Maori man but separated from him in the 1970s.
Ms Scoble said Ms Ngahooro made her burial wishes clear in her will.
"She asked to be buried in Hamilton. If she'd wanted to be buried on a marae we would have made sure that happened. She didn't want that," she told Prime News.
Ms Ngahooro's niece Catherine Mikkelson called for the law to be changed to stop body-snatching.
"The fact that she was actually able to do this just is mind-blowing. It's caused the most amazing amount of devastation that is just unexplainable."
Clashes over where a deceased person should be buried, and where they should lay beforehand, are not uncommon in Maori society. The clashes are usually an indication of the importance of the deceased and are strongly fought.
Many of the recent debates over body snatching ha ve been in cases where the family includes both Maori and Pakeha members.
The snatching of Mrs Ngahooro's body follows that of John Takamore in August last year and that of Tina Marshall-McMenamin in December.
Members of Mr Takamore's eastern Bay of Plenty-based whanau took him from Te Whare Roimata Community Centre in Christchurch, without the permission of his partner of more than 20 years Denise Clarke, and "brought him home" to be buried at Kutarere.
Mr Takamore had been due to be buried the next day in Christchurch, in accordance with Ms Clarke's wishes.
Ms Marshall-McMenamin's body was taken by her biological father Eugene McMenamin after her mother's family agreed to the funeral being held in Lower Hutt with Mr McMenamin driving her body to her mother's house.
Mr McMenamin took the body but he kept driving, with supporters blocking attempts of the family to stop him. She was buried on private land near Ruatoria, on the East Coast.
Ms Clarke has campaigned for a law change and Wellington lawyer Michael Bott said the law should be reconsidered.
"It doesn't appear correct that this person can be a law unto themselves. The wishes of the deceased as to the type of funeral they want basically is not legally binding but it morally is."
Funeral Directors' Association president Neil Little told Newstalk ZB that it wasn't right people could take bodies against the wishes of the deceased and their estate's legal executor but there was no actual law against it.
Mrs Ngahooro's body was due to be buried in Hamilton yesterday.
- NZ HERALD STAFF, NZPA