The New Zealand Transport Agency says about 60 per cent of second hand cars imported from Australia were written-off.

Experts warn car buyers should properly check second-hand Australian imports as most were write-offs.

About 60 per cent of used vehicles imported into New Zealand from Australia are statutory write-offs, amounting to about 240 vehicles per month, the New Zealand Transport Authority (NZTA) has revealed.

Car buyer Christopher Dear complained to the Motor Vehicle Disputes Tribunal last month, after discovering a Holden Crew Cab vehicle he'd bought from Ozcars Limited was classified by the Australian Financial Security Authority as a statutory write-off.

Ozcars claimed it had informed the buyer of cosmetic damage suffered to the car, and said it accepted the car was damaged but there was a "process" in New Zealand for which it could become certifiable.

"We accept the car was a statutory write-off in Australia, as are most car being imported from there. Most of our vehicles carry a 'damage' flag for various reasons and we have no problem with this or have any reason not to disclose this as it is clearly displayed on our CINs and this is our business model," the company said.

The authority found the damage flag had been removed by the NZTA because it wasn't structural, but it said the history of the vehicle should have been disclosed regardless.

It said the damage was more than cosmetic and that Ozcars had mislead the buyer and "despite its claim that it recognised that it needed to be deliberate and transparent in its dealings with the purchaser, was neither deliberate nor transparent".

Although the tribunal ruled Ozcars had mislead the buyer, it ruled the car was of acceptable quality and had "no choice" but to dismiss Dear's application to receive compensation.

In Australia a statutory write-off means the car has suffered damage so serious it can not be deemed roadworthy, or registered in that country again.

Just 7 per cent of vehicles inspected at the border were flagged as being damaged however, and in New Zealand they can be used for parts – or repaired and certified to be roadworthy.

In 2013 the NZTA required all Australian write-off imports to have a Personal Properties Securities Register check, after it emerged hundreds of imports weren't being flagged as damaged during routine border checks and certification.

New Zealand road safety advocate Clive Matthew-Wilson said cars imported from Australia all had various damage classifications. The practice of importing Australian write-offs was "relatively widespread" and it was possible to repair vehicles to roadworthiness, he said. "It can be done safely but what's really important is that people know about it."

He said some "unscrupulous" dealers would import with the intention of selling unroadworthy cars, or fail to disclose history to buyers.

"The onus is on the seller to tell the buyer," he said. Although buyers could investigate a vehicle's history independently, "not everybody does those checks".

NZTA acting group manager Leigh Mitchell said only seven per cent of vehicles that crossed the border were flagged as damaged. Any vehicle that was identified at the border as damaged or previously written off is listed in the damaged vehicles list on the agency's website.

Following an "invasive structural inspection" by officials, cars could be repaired and certified, but would still remain on the list, Mitchell said.

"We recommend vehicle buyers research their vehicle before buying it. This should include getting a pre purchase inspection report and to check on the NZTA website list to see if there is any info about the history of the vehicle they are thinking of buying," she said.