Vanuatu's foreign minister, Edward Natapei, says the government has cancelled the diplomatic passport of deputy ambassador of Vanuatu in Brussels and honorary consul of Vanuatu to Vietnam, Pascal Vuan Ahn Quan Saken.
Mr Natapei says it was cancelled in July, but Mr Saken has failed to return it.
The Principal Passport officer, Henry Tamashiro, says the next step is to follow him and confiscate the document when he uses it to travel.
Mr Tamashiro also confirmed that no passport has been sold.
The prime minister, Moana Carcasses, has denied opposition allegations that the government sold diplomatic passports.