Three people were arrested on Tamatea Rd after a petrol drive off from the BP in Bay View this afternoon.
Police received a call from the petrol station on Main North Rd at about 3.30pm after staff were alerted to a man filling a car up wearing a mask.
When an attendant approached the man he and the two passengers in the car became verbally abusive.
A police spokeswoman said the woman in the front passenger seat of the car also had a knife on the floor by her feet.
"The attendant decided not to take them on but told them they were going to call the police. The trio then drove off without paying."