A Māori defence lawyer who visited Standing Rock has slammed the escalating police presence at Ihumātao as "over the top" in what has been an "entirely peaceful process".

Those occupying the site of a proposed housing development in South Auckland claimed police staff manhandled at least one of them last night as they were blocked in by dozens of officers.

But police deny the claim, and say they only brought in extra numbers after the group earlier moved past the cordon onto private land. They also said officers had been subjected to physical and verbal abuse.

The group leading the occupation, Save Our Unique Landscape, claim as many as 100 officers turned up just before evening prayer around 7pm.

Hundreds of supporters flooded in to the site as a stand-off with police ensued, which lasted until about 1am. No arrests were made.

Defence lawyer King Snelgar observed the stand-off and said the large police presence was "very concerning".

"Especially given the entirely peaceful process working towards a resolution. This is not a violent situation at all, it was all very over the top."

Organiser Pania Newton said she was walking through a gate when a police officer rammed her with it - causing her to fall to the ground.

She said she was "fine'' and luckily, no one was seriously hurt.

Snelgar said he didn't witness that personally but was concerned about general police actions, and how they worked to isolate people during what was a very cold evening.

"A small group of protectors were at the frontline on a road, surrounded by police and isolated. They were not on 'private land'.

"What happened to the halt to development, finding a solution and de-escalation by police? The higher police presence suggests the opposite."

Snelgar, who works as defence lawyer in Manukau, has been providing legal advice and bearing witness at Ihumātao, along with a few dozen other legal professionals and students.

He said he'd never seen any physical nor verbal abuse from protesters towards police.

"There has been a lot of passionate singing, and tensions can boil over, but it has been mostly goodwill."

Snelgar spent six weeks as a human rights observer at Standing Rock in North Dakota in 2016, and saw some "pretty horrific" police action, including the use of dogs and concussion grenades, against protectors there.

"[Ihumātao] is a completely different situation, but there is concern, and we want to be here to make sure it does not escalate."

Counties Manukau District Commander Superintendent Jill Rogers said police increased their presence at the site after organisers indicated they intended to move past the cordon.

"Despite repeated warnings from police, a large group of protesters attempted to bypass the police cordon.

"Police attempted to stop those trespassing, but protesters pushed their way past our staff."

The group eventually vacated the private land and no arrests were made, she said.

Police rejected allegations a protester was pushed over and said misinformation was being circulated suggesting police had broken agreements.

She said staff had shown "incredible professionalism" over the last two weeks, despite at times being subjected to verbal abuse, being physically shoved and being spat on.

Auckland Councillors Cathy Casey and Efeso Collins said they were concerned at the increase in police numbers overnight at Ihumātao.

"The increased police presence at Ihumātao is running roughshod over the Prime Minister's proclaimed desire to enter peaceful and honest talks," Collins said.

"The cops need to be told to calm down and back off."

Two days after the occupation ramped up with supporters flooding in from across the country Auckland Council had voted to unanimously support a motion to bring all parties together to facilitate a peaceful outcome.

The following day, Friday July 26, Prime Minister Jacinda Ardern announced a halt to the Fletcher development while all parties, including all mana whenua, worked towards a solution.

Casey said they were calling on the Government to show good faith in their commitment to resolving the crisis by reducing the police presence.

About 80 protesters gathered outside Fletcher Building, the developer of the Ihumātao site, Tuesday morning as part of a "national day of action".