Police are investigating rumours that a person travelled to Wellington from Auckland to attend a large tangi in Porirua.
Inquiries are underway to establish the veracity of the information about the alleged traveller - police say at this stage there is no further detail to share.
Four vehicles were also impounded and two people were arrested for alleged offending after the gathering.
While inquiries are ongoing, police said in a statement that officers had identified a number of potential offences, particularly in relation to dangerous driving.
As a result, police said four cars have been impounded due to offending observed during the procession.
"Two people have been arrested to date - one person for disorder and a second person who had an active warrant to arrest."
Police said they were also not ruling out further arrests and/or vehicle seizures.
"We would like to thank all those members of the public who have been in touch to report possible offending."