A coroner says the New Zealand Transport Agency and police should look at closing a loophole that allowed a tourist to rent a car using an invalid foreign licence.
Two Chinese tourists died in a road crash near Te Anau in 2011.
Coroner David Crerar found driver Vivian Dong rented the car by providing her full Chinese licence, knowing her partial New Zealand one would not be accepted.
But having any New Zealand licence made her Chinese one invalid.
Mr Crerar says in Australia an overseas licence is marked as invalid once a domestic licence is applied for.
Christchurch-based car hire company Apex says there is no way at present for operators to know whether a customer has a New Zealand licence.
However, a spokeperson for the AA, Liam Baldwin, says that may not have prevented the fatal crash, as little can be done if someone is determined to break the rules.
The New Zealand Transport Agency says it will consider the coroner's recommendations.