Madrid ( CNN ) -- A gang that smuggled Chinese citizens into the United States and Europe , sometimes forcing them to work as prostitutes , has been busted with 75 arrests in Spain and France , authorities announced Saturday . The trafficking ring was based in -- and directed from -- China , but its two suspected leaders in Europe were arrested in the operation , in Barcelona , Spanish national police said in a statement . Besides the two main suspects , Spanish police arrested 49 others carrying forged passports at the airports in Barcelona , Madrid , Palma de Mallorca and five other cities . In France , there were 24 arrests . The smugglers charged 40,000 to 50,000 euros ( $ 53,000 to $ 66,000 ) to transport Chinese citizens , assigned with false identities , to the United States , Spain , France , Greece , Italy , Britain , Ireland and Turkey , the statement said . Spain was the next-to-last stop for many before they went to the preferred locations of the United States and Britain , the statement said . Twins rescued as China hospital trafficking probe continues . The arrests were made last June and the case , at Spain 's National Court , has been under seal until now , a national police spokesman told CNN on Saturday . All of the suspects are Chinese , or from elsewhere in Asia . All have had initial court appearances and have been ordered to remain in prison while the investigation continues or have been released by the judge , with conditions , said the spokesman , who by custom is not identified . The suspects include those who allegedly formed part of the smuggling ring and also those who paid for the forged documents , the spokesman said . Police seized 81 forged passports , ostensibly from Japan , Malaysia , Hong Kong , Singapore , South Korea and Taiwan -- but all made in China , they said . Investigators also found three laptop computers , printers and 22 rubber stamps used to forge documents at homes they said the gang used in Barcelona , police said . The probe began two years ago . Investigators said the trafficking ring was intricately structured , divided into independent and virtually isolated cells to avoid detection , police said . The smugglers used their own set of trustworthy travel enforcers , well-versed in the airports and cities where the Chinese were taken . They kept the travelers under control , sometimes trying to pass them off unnoticed among groups of legitimate Chinese tourists . The ring was quick to react to security changes on the ground at a given airport , swiftly changing to another destination where it would be easier to have their people slip past security controls , the statement said . Once a delivery of smuggled Chinese citizens had been completed , the travel enforcers would return to their bases in China and Malaysia to await further instructions , and to avoid detection by Western police forces , police said . Spanish police have been active in recent years in fighting human trafficking rings that lured citizens from Asia , Africa or Eastern Europe to Spain . The victims are often promised a better life , but then subjected to harsh forced labor conditions in clandestine factories or forced them into prostitution .
Smugglers charged up to $ 66,000 to bring migrants into Asia and the U.S. , police say . Western police arrested two suspects they called the ringleaders and two others . Another 49 were arrested in U.S. after a two-year probe .