Some Nigerians have been arrested in Germany for selling certificates to Nigerian men documenting fake marriages with Portuguese women in more than 70 cases, taking up to 13,000 euros ($15,600) each time.
At least 40 residences were searched in Berlin alone during the coordinated mass raids across Germany.
Raids were also conducted in Potsdam, Frankfurt and the eastern town of Goerlitz.
The federal police said there were at least 70 known cases so far with more expected.
In Berlin, police arrested four women between ages of 46 and 64 and one 50-year-old man who was said to be the head of the ring and had contacts in Portugal, helping them to recruit women from there.
The Nigerian men paid up to 15, 500 dollars for the documents to the ring, which shared some of the money with the Portuguese women.
Portuguese police aided in the investigation by prosecutors in Berlin, which had been ongoing since November 2016.
Have a story to tell, or images to share on a breaking news story? Send them to Shakarasquare WhatsApp or call