The interior ministry said airport officials had raised the alarm when they noticed a number of Guinea-Bissau passport holders who could not speak any of the country's languages.
"At this stage of the investigations, we have found 41 people carrying (illegal) Guinea-Bissau passports," including Cameroonians, Guineans, Nigerians and Senegalese, said Interior Minister Botche Cande.
He added that some of them "could be charged with a crime."
"Three of our officials involved in this case have also been arrested. Work is focused on the offices where civil status documents are issued," Cande said.
Interior ministry chief of staff, Braima Tcham, said the operation had been under way since 2022.
He said it involved a Cameroonian —who has been apprehended — acting as an intermediary between passport applicants and the migration and borders department of the interior ministry.
The officials in question issued birth certificates to applicants for a payment of around 400,000 CFA francs ($656).
The document was then passed to an associate in the identity cards department, and a passport duly signed by the minister was issued to the recipient.
Tcham said that more than 500 passports were issued to "people who are not Guineans."
"The ease with which (these) documents can be obtained is leading more and more would-be immigrants to come and collect the precious document in Guinea-Bissau in order to travel," he added.
French newspaper Liberation in 2021 revealed trafficking of diplomatic passports by the Guinea-Bissau government in France.
Guinea-Bissau Cracks Down on Passport Fraud
FILE - The cover of a U.S. Passport is displayed in Tigard, Oregon, December 11, 2021.
BISSAU —Guinea-Bissau's interior minister on Monday said that police had dismantled a passport fraud network within the ministry, and that three of its officials involved in the case had been arrested.