Police in Spain, France and Paraguay have arrested around 14 people and freed up to 15 women as part of a joint operation against sex trafficking.
Spanish police said in a statement Sunday they arrested nine people in the northern city of Pamplona on sex trafficking charges and liberated four exploited Paraguayan women.
They said the operation started after one of the victims dialed the Spanish help hotline against human trafficking in December 2015, although the ring started its criminal activity back in 2010.
The raid was a joint effort with authorities in France and Paraguay, who also made arrests and freed women in simultaneous police busts.
The arrests were made over three days, starting Tuesday. Among those detained in Pamplona were three of the alleged ring leaders of an international criminal organization based in Ciudad del Este near Paraguay's border with Brazil and Argentina, police said. Police in France raided a location in the north-western city of Nantes.
The supposed boss, a woman in her 40s from Paraguay with Spanish nationality, was the only one that remained in custody after the other eight detainees were issued court dates and advised legal counsel.
The police said the organization had a family clan structure involving up to eight brothers with criminal records, who preyed on young women eager for a better life in Europe away from their impoverished background.
"They sought out their victims and promised them jobs in France and Spain as masseuses, housekeepers, or staffers in local supermarkets," said Fernando Cegonino Ananos, chief Pamplona investigator from the Immigration and Frontier brigade.
"It was a scam operated by a family clan that included the arrested ring leader, her husband and sister in Pamplona, and mother in Ciudad del Este, where they went through a travelling agency to set the wheels in motion," he added.
Once the women reached their destinations, travelling through Sao Paulo in Brazil, they found out that their true task was to serve as prostitutes in the ring's many strip joints, bars and establishments camouflaged as massage and beauty parlors, he said.
They were kept under strict vigilance by clan members and were told that they owed the criminal group up to 3,000 euros ($3,400) in travel fees.
"This was a violent crew that coerced their victims through physical harm and constant surveillance," Cegonino told The Associated Press. "One of the arrested culprits in Paraguay was an ex-cop that had to leave the force because of robberies and came to Spain, where he was also charged with domestic violence before going back to his native country."
Police said the women were forced to sign documents recognizing their debt, were occasionally beaten and got moved around from Pamplona to France in order to break their routine with clients.