Police are investigating after an aggrieved hapu member cut off a Crown limousine carrying Andrew Little, blocked the road, and then issued the Treaty Negotiations Minister a "trespass notice".

Andrew described the protest as "an act of lunacy," but the Opotiki-based Ngai Tamahaua hapu says the minister had been warned he was not welcome and should have stayed away.

Speaking to RNZ, Andrew confirmed a car overtook the VIP vehicle he was in and "came to a sudden stop" near Opotiki on Friday afternoon.

A man then jumped out of the car and handed over a piece of paper that "purported to be a trespass notice," he says.

"This was an act of lunacy by a lunatic."

Andrew says the document was meaningless as he had been on a public road - State Highway 2 - and it would not stop him returning to the area.

"I expect to be back in the region fairly soon actually. I'm not going to be put off by the actions of a lone actor."

Police confirmed they were aware of the matter and were making enquiries.

Andrew says he would make a statement to them in the next few days.

Ngai Tamahaua - a division of eastern Bay of Plenty iwi Whakatohea - issued a media release claiming responsibility on Tuesday and said the move was a plea for the minister to listen to it.

Hapu deputy chair Tim Herewini told RNZ one of its members took action in protest over the minister's handling of their Treaty negotiations.

"The reason Andrew has been trespassed is because he is an existential threat to the sovereignty of the hapū and to our survival and to our future."

Tim would not confirm who had served the notice, but insisted they had been "officially authorised" by the hapū.

"The operation was done very carefully, very professionally, with safety in mind ... and it was conducted very courteously as well."

Tim says Andrew had previously been warned not to come into their rohe, or territory, and to ignore that was a "provocative act".

"The minister had been informed well in advance that if he did try to do this, or any of his officials did, that he would be intercepted at the earliest opportunity, trespassed and then escorted out."

The dispute centres on who is mandated from Whakatohea to negotiate its Treaty settlement with the government.

A Waitangi Tribunal report last year ruled the Crown had unfairly negotiated a $100 million deal in principle with a group that did not have the backing of the whole iwi.

The Crown recognises Whakatohea Pre-Settlement Claims Trust, but Ngai Tamahaua and other hapu reject the trust's mandate and accuse Andrew of trying to steamroll ahead.

The Waitangi Tribunal has since launched an inquiry into the historical grievances of Whakatohea.

Former Whakatohea trust board chair and treaty claim negotiator Tuariki Delamere says he also had concerns about the settlement process, but Ngai Tamahaua's actions went too far.

"In these days of worldwide terrorism threat, to have someone drive up on a ministerial car and cut them off is totally inappropriate," he says.

"We're not that far from a situation where ministers could well have armed police with them and you could have a shooting match."

Andrew says the latest action would not dissuade him from working with Whakatohea to resolve its internal conflicts.

"It's not unusual for there to be elements within an iwi who disagree. What I do know of this person is he doesn't represent anybody - he represents himself. My job is to deal with iwi and hapu, not individuals."

Opposing hapu - Ngati Ira - spokesperson, Te Ringahuia Hata, says she wasn't sure how the event played out exactly but she wasn't surprised it happened.

Hapu had been opposing the minister going into that rohe without engaging with them, especially when he was returning from a signing of an agreement in principle with Te Whanau a Apanui, she says.

"From my perspective he has to understand the dynamic within Whakatohea where there are cross claims also happening between Whanau Apanui and Whakatohea, it isn't surprising Ngai Tamahaua would take that action."

She says Andrew hadn't engaged face to face with hapu opposing the settlement and from a tikanga perspective it was about courtesy - if you were going to go through their whenua, then meet them.

"So from a hapu tikanga perspective if that is the only way that they could make the minister understand and realise that until he engages with hapu and Whakatohea they are going to keep blocking the roads that cut across their land."

-RNZ/Craig_McCulloch