Masterton mechanics are scratching their heads over a mysterious radio frequency interference on Queen St which is leaving some shoppers unable to unlock or start their cars in the area.

Mechanic Ewen Stark of Nick's Auto Services said the problem had been going on for at least six months in the three parks outside the kebab shop and Ten O'Clock Cookie Bakery Cafe.

"There's obviously an interference, something in the area that's putting out a signal and causing trouble. Holdens are the worst at the moment, but I've had Toyotas that have done it, and I've had a Suzuki that's done it too."

He said the frequency interference affected the immobiliser and transponder of the car. Common callouts to the area involved car keys not working to remotely unlock the car, and an inability to start the car after it is unlocked manually.


"With some Holdens we can override the system, but generally we just have to tow the car 100m up the road and then it will start just fine because there's nothing actually wrong with the car.

"I had a Holden Cruze here on Saturday and the job came through to me from the AA through Holden NZ. They basically told me exactly what the problem was before I went, so they are fully aware of it. They just requested me to tow the car up the road."

Mr Stark said he normally gets called out once a month to respond to the problem in that area but that "sometimes there can be one or two in a week".

Wagg's Service Manager Gary Bishop said he was called to the area "at least once or twice each week" and that the cause of the interference was a "total mystery".

"We don't really have much more information on it, we're just trying to work out what the hell it is," he said.

"Whether there's a new satellite dish somewhere gone up or one of the shops has something in with their electric doors, we really don't know."

The bizarre phenomenon has occurred throughout the world in recent years, with a commonly identified culprit being wireless devices used by nearby shops. These devices can unintentionally jam the same frequency used by particular key fobs in unlocking cars.

In Masterton, surrounding businesses to the parks, including Bay Audiology and Flight Centre, were asked if they had noticed the problem but all staff said they were unaware of any problem.


Staff from Hannahs Shoes, across the road from the three parks, said the only thing they had noticed was that quite a few car alarms had been going off in that area lately.

This was also noted by staff at Ten O'Clock Cookie Bakery and Paper Plus.