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 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 dialled the Spanish help hotline against human trafficking back in 2015.
The raid was a joint effort with authorities in France and Paraguay, who also made arrests and freed women in simultaneous actions by police.
They did not specify when the arrests were made, or when the women were liberated.
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.
They said the organisation had a family clan structure and preyed on women eager for a better life in Europe.
They allegedly sought out their victims and promised them jobs in France and Spain as masseuses, housekeepers, or staffers in local supermarkets.
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 and bars, police said.
They were kept under strict vigilance by clan members and were told that they owed the criminal group up to €3,000 in travel fees.