Niue's chief of police Tony Kose has told the island community if they want to erect protest placards they should get permission from the police first.
In an interview on local TV news Mr Kose said the incident involving the jailing of a protestor during the New Zealand prime minister's visit to Niue was still under investigation and no decision had been made on whether or not to charge the protestor.
Vilikai Vilikai alleges he was assaulted by police who removed his roadside signs and was locked up for 10 hours during John Key's visit on Wednesday.
He later sought medical attention at the Niue Foou Hospital.
He is seeking legal advice after alleging he was unlawfully detained.