Motorists should stop taking the law into their own hands and stop taking foreign drivers' keys, the Prime Minister says.
There have been at least five incidents in recent weeks where keys have been taken off tourists by concerned drivers. In one case, a tourist was punched in the face.
The latest reported incident occurred on the Otago Peninsula on Saturday when Dunedin man Robert Penman took the keys from an Asian driver who had pulled over on a narrow road to take photographs.
Listen to John Key
John Key said these cases needed to stop.
"I really would advise people not to do that. I think people taking the law into their own hands is not sensible. We see that with people from time-to-time, for instance, if they see someone who's clearly under the influence of alcohol or drugs. The very sensible thing to do is ring 111."
Listen to Mary Wilson's interview with Dunedin man Robert Penman
The police are warning people they may face charges if they continue to take tourist drivers' keys.
Southern District Commander Andrew Coster said key snatchers could face punishment.
"It's not beyond the realms of possibility that that could occur. My sense is that the public are smart enough to understand the message that we're giving, which is that we're the best equipped and positioned to respond and deal with these situations."
Mr Coster said there were hardly any circumstances where taking keys was justified.
Tourist driver 'abuse' giving NZ bad image
The Rental Association said the country was gaining a bad image overseas from reports of New Zealanders abusing tourist drivers.
The association's president, Ian Berrington, said it was not as simple as stopping people from renting vehicles, as New Zealand was a signatory to the United Nations convention on traffic.
The convention was designed to facilitate international road traffic, and allowed citizens from countries that have signed to drive without restriction in other signatory countries.
But Mr Berrington said steps to improve rental systems were underway.
"Our focus at the moment is in seeing what we can do in the educational sphere.
"We would also encourage anything that can be done in terms of improving roads, improving signage, we are encouraging the government to get on to that."
He also said that, statistically, tourists only contribute to a handful of accidents in New Zealand.
Apex Car Rentals said driving conditions in New Zealand were like nowhere else, so driver education was vital.
Reservations manager Tony Quinlivan said tourists were sent a driving video, written material and strong visual material before they arrived in the country, and even the small number who did not pre-book were given the material when they arrived.
He said driving simulator tests were not the answer as people could be great in the simulator, but hopeless on the open road.
"I could put my 11-year-old in a simulator and he could drive perfectly well.
"Does it then mean he is capable of driving on the open road? Definitely not.
"That's not going to be the answer. And to me, it is more and more about education," he said.
Automobile Association general manager of motoring affairs Mike Noon said some information for foreign drivers needed to be in their home language.
"The information which is given to drivers when they are first picking up their rental car in New Zealand should absolutely be in their home language.
"So we are very clear then that there is no misunderstanding," he said.
"I do however think it would be impractical to put the signs in different languages, because you'd just need too many signs."
Mr Noon said drivers should take keys off tourists only as an absolute last resort.
He said motorists were working themselves into a frenzy over tourist drivers.
"The key thing here is in the first instance to contact the police.
"If you have been following a driver that has been erratic, then maybe go and speak to that driver and say to them look, we have put a call in, can you please wait here. Taking keys is very much a last resort."