Wealthy foreigners are stashing their money in New Zealand and using the country as a tax haven, Labour says.
Revenue spokesman David Clark says the number of foreign trusts operated by "overseas billionaires" has almost doubled since the government came to power in 2008, and they're getting away tax free.
"There is a serious ethical issue here," he said on Monday.
"These people, who are often rich families in poor countries, aren't paying their fair share and that's not something New Zealand should be supporting."
Dr Parker says New Zealand is in danger of losing its reputation as an ethical and respectable country.
Revenue Minister Peter Dunne says his claims are nonsense.
"The key identifying characteristics of tax havens are secrecy and lack of transparency," he said.
"Those are simply not factors here in New Zealand."
Mr Dunne says legislation for taxing trusts was introduced in the 1980s and is fully transparent.
"Deliberately artificial tax structures designed with the purpose of defeating New Zealand's tax laws will attract Inland Revenue's scrutiny."