A major German police operation on Tuesday involving more than 570 officers resulted in the arrests of four people suspected of heading a gang of human traffickers.
Police raided 50 flats in three German states, a police spokeswoman said. Four suspects – three men and one woman – were arrested.
They are thought to have arranged some 200 cases of fake marriages. One of the men is Serbian, and the others are German.
The vast majority of the flats searched were in the capital Berlin, but there were also raids in Brandenburg, the region which surrounds Berlin, and North Rhine-Westphalia.
Investigations have been ongoing since October 2017.
The gang aimed to secure permanent residence in Germany for people, mostly men, from Pakistan, Nepal and Albania through the fake marriages.
Each union could cost up to 16,000 euros (18,260 dollars).
“This sometimes made people dependent,” a police spokesman said.