A Māori Party candidate was one of four people arrested for trespassing in Hamilton on Monday, while trying to stop survey work for a new roading development.
Descendants of a Waikato-Tainui hapū, Nga Muri Kaitaua, gathered on the privately owned land to stop the soil sampling.
The site is part of a planned road, which local Māori say will run over their old pā site, Nukuhau, and an urupā.
Police said four people who refused to leave after being issued a warning were arrested.
Māori Party candidate for Hauraki-Waikato Donna Pokere-Phillips was one of them.
She said the charges had since been dropped.