Protesters at a rodeo in Whangārei are considering asking the police to prosecute spectators who pushed and verbally abused them.

Warning: strong language.

Six anti-rodeo activists bought tickets and entered the Mid-Northern grounds at Kokopu Block Road yesterday.

Mid-Northern club member Dianna Bradshaw said the club had a strict no high-definition cameras policy, which had been in place for over a year, and the group had already been asked twice not to film.

She said when the activists began filming for a third time some spectators and cowboys became upset that they were not respecting the rules.

"I was yelling 'don't touch them [the activists]', but what did they think was going to happen. Did they think they could come in and not expect people to be upset?"

She said the demonstrators were being "obtuse" by refusing to comply with the club's policy and some of them were evicted from the grounds, which are private property.

Anti Rodeo Action NZ activist Josh Howell said their presence was announced over the speaker system, which escalated the situation.

"People tried to block us. It was quite chaotic. I personally felt quite threatened."

"People started getting cameras knocked out of their hands and pushed. I was being pushed. I was also attempted to be tripped up as we were leaving. We were being sworn at and shouted at."

Another activist Claire McRae said she began filming again after seeing a bull bucking in the chute prior to entering the arena.

"When the bull riding started we saw that one of the animals looked quite agitated in the chute and we thought it would be a good chance to get some footage and so I did pull out the HD camera again at that point."

"It was pretty intimidating, very quickly we got surrounded, someone was trying to wrestle my camera out of my hands and the guys behind me who were filming they got pushed and shoved as well."

Ms Bradshaw said filming on high-definition cameras was banned because the images could be edited and manipulated and used out of context.

But people were welcome to film on their phones.

However Ms McRae said they were told to put the phones away too and one of their phones was stolen by a spectator.

"There was particular emphasis on not being able to film the roping event - the calf roping event - because they acknowledge that it's particularly controversial.

"They said we don't want you filming at all even on your phones the calf-roping because one image can be taken out of context."

"The police later retrieved the phone, the footage had been deleted off it but at least it was in one piece so that's good."

Ms Bradshaw said she feared incidents like this at rodeos would only get worse.

"These people have an agenda, they're not coming to these events with an open mind.

"We're doing everything we can. MPI [Ministry for Primary Industries] was here all day, animal welfare officers were here. These animals are so well cared for and loved."

"There were no injuries at all yesterday."

Ms McRae said the group would discuss whether or not to lay a complaint with police.

"We are considering it. We have to debrief and think about where we go from here. Especially the guys who got pushed around a bit they may be considering it."

Police said they provided a brief presence at the rodeo and no arrests were made.