The briefing also warns of problems in providing infrastructure in areas with small rating bases and high tourist numbers.
Tourism Industry Association policy and research manager Simon Wallace said any move to charge international visitors to access assets such as national parks was unlikely to be welcomed by the industry.
"There are a lot of tourism concessionaires operating in national parks who guide and host international visitors anyway, so international visitors are contributing to national parks by booking trips with these tourism concessionaires."
He cited Department of Conservation research showing tourism concessions generated $51 million a year in Fiordland National Park, and a further $13 million in a flow-on effect for the Southland region.
Southland District Mayor Frana Cardno said "national parks are there for everyone" including international visitors.
"We are charging in lots of places. People are paying to walk the Milford Track."
Mrs Cardno said she was supportive of a tax charged on arrival at the country's international airports, which could pay for essential tourism infrastructure and alleviate the ratepayer burden for those living in small tourism centres.
A spokeswoman for Mr Key confirmed officials were looking at the issue of regions with small rating bases and high tourism numbers "because of the infrastructure challenges they face".
- OTAGO DAILY TIMES