Wellington police are urging people to come forward after receiving suggestions that sexual assaults may have occurred the protest at Parliament.
Police Assistant Commissioner Richard Chambers said police were the only agency able to investigate sexual assaults.
"If anyone would like to come forward to us, to talk about what may have occurred to them then please do come forward and we will work with you as best we can."
Police earlier said they were "extremely appalled" by the behaviour exhibited by protesters at Parliament.
Three officers were taken to hospital for a medical assessment this morning after being sprayed with a stinging substance that is still to be determined.
"Other officers were fortunate to escape injury after a person deliberately drove the wrong way down Molesworth St and stopped just short of colliding with them," police said.
It came as about 250 officers this morning tried to further reduce the perimeters around the protest site.
"This work is part of our ongoing efforts to reduce the impact of the protest on Wellingtonians, particularly those who live, work and study in the area around Parliament."
During this process, police said two people were arrested for obstructing police and one person was arrested for driving in a dangerous manner.
"As we stated yesterday, it has become increasingly clear that genuine protesters are no longer in control of the behaviour in and around Parliament."
There have been numerous reports over the past 15 days citing anti-social behaviour by protesters, including abusing passers-by - among them children - for wearing masks, and surrounding streets and buildings have been overtaken by tents, campervans and cars.
Yesterday police confirmed some protesters had hurled human waste at officers.