AN increasing number of cases involving huge sums of counterfeit money have been uncovered, many involving collaboration with criminal groups abroad, according to a report. The China News Service in Hong Kong said yesterday that 10 yuan, 50 yuan and 100 yuan notes were the main counterfeits found circulating in the market in China. Nearly all cases cracked by authorities involved triads and other criminals from Taiwan, the report said. According to official statistics, the Chinese Industrial and Commercial Bank collected fake notes totalling more than 13.84 million yuan (HK$12.28 million) last year alone. The report said fake yuan from Taiwan had greatly disturbed China's financial markets. Quoting ''responsible officials'' in the money issuing department of China's People's Bank, the agency said that besides counterfeit yuan, other fake foreign currencies and state bonds were also found circulating in China. However, prompt action by banks, public securities and Customs authorities had succeeded in slowing the inflow of fake notes, the report said. Last October, more than 130,000 yuan in counterfeit notes was uncovered in a village in the coastal Fujian province. Two months later, 100,000 yuan in fake 100 yuan notes was confiscated by Fuzhou authorities.