Border police have detained 22 suspected gang members and seized more than 35,000 fake foreign visa documents in a crackdown on illegal emigration from the Pearl River Delta city of Jiangmen in Guangdong province.

The gang arranged for more than 3,200 people to be transported abroad over several years, border police said in a statement. Most of them were transported by plane to Russia or to South American countries for illegal employment, Tuesday's statement said.

The enterprise, which involved more than 220 million yuan ($34.5 million), was the largest case of illegal emigration from the Chinese mainland in a decade, said Luo Wei, the officer in charge of the case.

The gang "even operated a licensed travel agency to act as concealment for its illegal events," Luo said.

Police said 1,500 of the emigrants were from Guangdong, 1,300 were from Fujian and 400 were from Guangxi Zhuang autonomous region, Guizhou, Sichuan, Hubei, Hunan, Anhui, Shanxi, Heilongjiang and Shaanxi provinces and Chongqing municipality.

Police seized 270 fake official seals and related materials after busting the gang, froze bank accounts valued at more than 11 million yuan, sealed three gang-owned properties and recovered computers, passports and luxury cars. Police are still pursuing additional escaped suspects, Luo said.

The detainees included six organizers responsible for collecting passports, applying for visas and arranging routes; four people responsible for producing fake certificates and related documents; and 12 who organized and transported residents abroad, Luo said.

All of the emigrants, who held valid Chinese passports, received special anti-detection training before being transported, he said.

The gang typically paid the expenses for the illegal emigration first, then the emigrants were required to work for two to three years to repay the organizers, he said.

Jiangmen border police set up a special task force to investigate the case after border police at Shenzhen's Huanggang checkpoint detained 12 emigrants from Jiangmen and a suspected organizer last year.

After months of investigation, police raided four fake document production bases and detained the suspects in Guangdong's cities of Guangzhou, Shenzhen, Foshan and Jiangmen, Fujian's capital Fuzhou and Beijing in more than two dozen special police operations earlier this year.

Last year, six emigrants were repatriated to the mainland from Russia with the cooperation of Interpol.