More officers are being called in to police an influx of Australian motorcycle gang members expected to arrive in Christchurch from Saturday.
Detective Inspector Greg Williams says about 40 members of The Rebels were due to arrive then and would be joined by another 40 gang associates in the region, on what is known as the poker run.
The Australian gang has been attempting to establish itself in New Zealand since the beginning of the year.
Mr Williams says police have already seen evidence of violence as a result of The Rebels recruiting in Canterbury.
He says the only reason they would be coming to New Zealand is to make money from the drug trade.