The New Zealand Prime Minister, John Key, says he hasn't received any advice about whether holders of illegal Tongan passports are smuggling drugs into New Zealand.
Yesterday the Tongan parliament heard people with falsely-issued diplomatic passports may have trafficked millions of dollars worth of drugs into the country.
Mr Key said the allegations were not raised with him during last month's visit by the Tongan Prime Minister 'Akilisi Pohiva.
"We have real concerns about what effectively in one sense are legitimate passports but they're being used illegitimately," he said.
"We've had assurances from Tonga that they're dealing with the issue, he says some of it obviously predates his government and he's addressing it."
Mr Pohiva, has admitted there is a problem but told parliament he didn't know what to do about it.
But he suggested authorities were struggling to rein in corruption.
"There has been a continued sales of Tongan passports and this is a very serious serious case and our government is working very hard," he said.
"That is an indication of corruption. Law and order, the rule of law is very weak for quite some time," he said.
A royal commission to investigate the scandal was approved by the King of Tonga last year and parliament is awaiting a police report.