The Vanuatu Citizenship Office is appealing to people believed to be naturalised citizens to surrender their citizenship certificate if they have been granted it after residing in Vanuatu for less than 10 years.
The secretary general of Citizenship Commission, John Ware Enock, has given them an ultimatum until Friday next week to return the fake documents.
Mr Ware says the Commission is well aware of a well established group of people that has been issuing fake citizenship certificates.
He says his office is also aware that many have then used these fake documents to obtain Vanuatu passports.
Police have already arrested suspects in regards to the issuance of fake citizenship certificates and they will appear in court this month.