About 20 police including officers from the armed offenders squad have been involved in the arrest of a man in Reefton this morning.
Senior Sergeant Tim Crawford said the early-morning operation was to locate and arrest the man, who is now in custody in Greymouth.
Inspector Jack Canning said the man, who was middle-aged, was arrest in relation to an allegation of making threats.
Mr Canning, the Greymouth area commander, said the man was yet to be formally charged.
