Armed dial-a-tinny drug dealers are stepping up their operation in Auckland, delivering drugs to workplaces and hospitals, and touting for customers by handing out business cards in local malls, police say.

The gang-linked dealers are also carrying out standovers to steal vehicles and are trading cars in when they know they are "hot".

Police say the crews, aged in their late teens and early 20s, are routinely being caught in cars laden with cannabis and cash and with cellphones full of text message orders.

"It's absolutely rife and when you speak to anyone on the street, it's blatant - they're handing cards out - every area seems to be doing it," Acting Sergeant John Nicol of the Counties Manukau Road Crime Unit said.

Nicol said the operators came to their attention during an operation late last year targeting the high number of burglaries in Mangere.

"A lot of the guys that are associated to this are the burglars or receivers of the stolen property," he said.

Police had believed the problem was concentrated in Mangere but the recent arrest of two crews in two days in Manurewa showed it was more widespread and that the crews are armed.

A boning knife was taped to the steering wheel in one car pulled over by Nicol two weekends ago - made to look like a steering wheel adjustor.

"He's got that for the sole purpose of defending or making sure he's not stoodover while he's doing what he's doing."

Cellphones are routinely full of text messages relating to the sale of drugs, with many numbers saved under the address they were delivering to.

Nicol said they believed it was a different gang running the operations in different areas - the Mongrel Mob in Manurewa, the King Cobras in Mangere and the Tribesmen in Otara, with the crews getting the drugs from gang middlemen.

The main group in Mangere consists of about 20 people who have up to four or five crews operating at any one time, with two or three people per vehicle - which they regularly swap.

"At one point we had information that they were trading the vehicles in when they got hot," he said.

"A lot of the time the vehicles are clean vehicles that are registered to female partners who aren't known to police and stuff like that."

They were even doing business openly in the Papatoetoe car yard where they traded in their cars.

There had also been several suspected standovers where clients had been "taxed" over their vehicles in Mangere - including two incidents this year where a shotgun and threats of violence were used.

The Mangere crew, related to the King Cobras, had previously been caught with a sawn-off shotgun.

 

The crews are also delivering to Middlemore Hospital and other places of work, Nicol said, although it is not known whether it's employees or patients buying drugs.

Police also had information that the gangs in Manurewa were going to places such as the  Manukau Mall and handing out their business cards to people.

Some of the crews live together, including one group of Somali background who lived in refugee housing, and many had family gang connections.

"They're all sort of in the same area, they're all mates from school or whatever... and they've all come under the wing of the King Cobras.," Nicol added.

One of those caught was a 17-year-old girl in Manurewa who also assaulted an officer.

A Middlemore Hospital spokeswoman was "absolutely unaware" of anyone delivering cannabis to the hospital, but said the car park was a public area.

If people turned up saying they were family members, hospital staff had to accept that, she said.