Opponents of the Mt Messenger bypass project in Taranaki are claiming they have bought an old section of state highway they were trespassed from earlier this month.
They paid Land Information $400 for the 424 square metres of land - but the government agency says it is not selling and does not want their money.
On 4 November up to 80 police moved to trespass about half a dozen protesters from a lay-by area know as "the rock" on the northern side of the mountain.
It used to be one of the numerous windy bits of State Highway 3 and made a good protest base.
Marie Gibbs of the Poutama Charitable Trust claimed Waka Kotahi had no right to trespass them from the land.
"What we found was that it was a parcel of land that had no title so as far as we were concerned it was still in aboriginal title, so the ownership sat with Ngā hapū o Poutama."
Gibbs said the land was confiscated from Ngā hapū o Poutama in the 1860s.
"In 1987 they gazetted it 'stopped road' and we're not quite sure what that means because they never issued a title to it.
"Now that it's 'stopped road' and the Crown doesn't need it for roading any more under the Public Works Act they are needing to return it to the original owners."
Gibbs said the land was valued at $400 on the regional council property information webpage and they had paid that amount to Land Information to secure it for the uri or descendants Ngā hapū o Poutama and Ngāti Tama.
The elbow of land is a convenient protest site, but owning it would not obstruct the huge construction project, which will destroy about 30 hectares of native bush.
Ngāti Tama iwi member Robyn Martin-Kemp was one of a handful protesters still on the mountain.
"We did research the area because we are aware that some of the land is in the NZTA project area, so when our team looked at it we found that it was actually a clear title.
"So we thought when we set up our camp there would be no issues. We've already paid for it, so we see it as being ours."
Martin-Kemp said the trespass action was designed to unsettle the protesters.
"I do get hoha (annoyed) because they're being petty, you know, we're a peaceful occupation we're just bringing an awareness of the destruction that's happening in that ngahere (forest) and the Mangapēpeke Valley.
"But we have to maintain our peace and calmfulness, so that we can stay on our land for as long as we possibly can."
Waka Kotahi referred questions about the "stopped road" to Land Information, which confirmed $400 had been put into the agency's bank account.
In a statement, head of regulatory practice and delivery, Rebecca McAtamney, said the protest group had also written to the chief executive asserting it had bought the land.
She said it was not for sale.
"The land is not currently available for purchase. As it is owned by the Crown, the land is subject to the Ngāti Tama Treaty of Waitangi settlement. The Crown is not in the process of selling this land."
Ngāti Tama are recognised as manawhenua in the bypass project area and iwi leaders have given it their blessing.
McAtamney said Land Information had returned the $400.