Five Nigerian men have been arrested by German police for allegedly smuggling Nigerian men into the country through arranged marriages.

A statement by the German police said 400 police officers raided 41 apartments and rooms suspected to be linked to the gang in Berlin and other German cities.

Reuters reported that the gang’s suspected leaders – four women and a man, ranging in age from 46 to 65 – were arrested.

Germany’s newspaper, Bild, said police investigation conducted with Portuguese authorities and Europol, revealed that no fewer than 70 men were brought in illegally through arranged marriages with Portuguese women.

According to the police, Europol, the European Union’s law enforcement agency, served as the host for operational meetings between the Portuguese and German investigators.

Clients had paid up to €13,000 for fake certificates, with part of the sum going to women who would fly from Portugal to join their “husbands” at the German immigration office to apply for an EU residency permit.

Similar cases were detected in June when the police found out that more than 700 German men in Berlin had married pregnant asylum seekers for money.