Four men posing as police officers are becoming bolder when approaching members of the public in Northland, police say.
Whangarei officers are hunting for the four who are apparently posing as plain-clothes police, with red and blue flashing lights on top of their red Holden Commodore.
The men have reportedly been pulling drivers over and asking to search their vehicles for alcohol and asking how much money they have with them.
Whangarei and Kaipara police area commander Inspector Tracy Phillips said it was concerning that between two reported incidents it appeared the men were becoming bolder.
It is thought they stopped a first car on February 9.
When a second car was stopped on Otaika Rd last Sunday, the bogus officers were much more forward and searched the vehicle.
One of the men had asked the female driver for ID and questioned her about the amount of money she had in her possession.
When the woman started to question the four about the validity of the stop they said they had another job to do and sped off.
Ms Phillips said the flashing red and blue lights were not from any of the Northland police patrol cars and they were easily bought off the internet.
As the search continues, Trade Me is defending the sale of police lights on its internet auction site.
Trade Me's head of trust and safety, Jon Duffy, said selling police lights was not illegal and students often bought the lights for their flats or for discos.
However, it is an offence for anyone to buy the lights, put them in a vehicle and use them in a way that creates the impression he or she is a police officer.
Ms Phillips said if people doubted the validity of a police officer's identity they could ask for the officer's name and dial 111.
The Holden Commodore used by the men is believed to have a registration plate ending in 506 and anyone with information about the imposters can contact police on 09 430 4500 or call Crimestoppers on 0800 111 555.