The issue of who is responsible for recalls affecting privately imported used vehicles from Japan is again in the news in New Zealand.

The Dominion Post reported that up to 600 faulty Isuzu Wizard and Isuzu Bighorn [Jackaroo/Monterey/Trooper] vehicles could be on the country's roads, their owners unaware that diesel leaking into the sump could cause them to suddenly speed up.

The official Isuzu vehicle importer is the local General Motors Holden operation, whose spokesman Peter Zoldak told the paper the company notified the Land Transport Safety Authority in March that 234 Isuzu and Holden Monterey vehicles built between 1998 and 2000 and sold new in New Zealand were to be recalled.

The owners of the vehicles were notified but nobody told the owners of [privately imported] used Japanese imports, the paper noted.

"We don't have any information about what used vehicles are in New Zealand," Zoldak reportedly said.

He told the Dominion Post Holden would replace free of charge the faulty fuel injector O-ring on the recalled vehicles but he said it would not pick up the $NZ500 cost for used Isuzus imported from Japan, though Mitsubishi picked up the costs last week for the owners of more than 343 possibly faulty Galants imported secondhand from Japan.

"It is not our responsibility, it is the responsibility of the people who imported them," Zoldak reportedly said, adding that no used Holden Montereys were brought in from Japan.

Authority spokesman Andy Knackstedt told the paper Holden was not legally obliged to fix vehicles it did not import - a safety recall of all vehicles was not issued immediately, as there was no record of ownership for them.

The defect was not considered to pose an immediate danger to drivers, he reportedly said.

Knackstedt told the Dominion Post the authority was talking to the Motor Industry Association to find a way to notify the owners of used Japanese imports if vehicles were recalled in future.