Police have arrested 18 members of a gang who smuggled more than 400 illegal Albanian immigrants into the UK and the US using fake French identity cards.
The operation was led by the Spanish National Police and Europe's crime agency, Europol, to break up the international crime group.
The arrests took place in the seaport of Tarragona, in Spain's north-east.
Agents also raided houses, resulting in the seizure of forged documents, financial documents, records of illegal activities, electronic equipment, cash and various narcotics, including cannabis, cocaine and synthetic drugs.
The two-year investigation has led to 46 arrests so far.
The breakthrough came when police went after a group operating in the UK and Ireland who were managing the flights and logistics for those entering the country.
It led to the identification of a key player in Spain who was enabling the operation.
“Intelligence shared by the US Department of Homeland Security and Homeland Security Investigations led to the identification of a high-value target in Spain,” Europol said.
“From there, the suspect and his accomplices facilitated the illegal entry of migrants through various airports in Spain and Portugal into the United Kingdom, while providing them with forged French identity cards.”
The operation in Europe is also connected to three continuing criminal investigations in the US.
“The investigation was launched in 2019 to examine the growing use of specific types of falsified documents by Western Balkan immigrants,” Europol said.
Previous phases of the investigation have led to the dismantling of a group of criminals identified on the Caribbean island of Sint Maarten who smuggled Albanian immigrants with fake documents into the US.
In December last year, couriers travelling to Kosovo and Albania to distribute the fake documents were also arrested.
Four shops printing forged documents in Kosovo were dismantled in March, more than 400 migrants have been identified at airports and more than 1,000 fake documents have been seized.
Last week, in a separate investigation, the UK's National Crime Agency arrested an Afghan man accused of leading an international people-smuggling network, carrying migrants to the UK from northern Europe in lorries.
Gul Wali Jabarkhel, 32, who was detained in north London, appeared in court on Saturday.
He is accused of being a high-ranking member of an Afghan crime group with links to other criminal organisations in Belgium.
They reportedly planned to use corrupt lorry drivers to carry out the operation.
