Police investigating a festive-season flood of counterfeit cash into the city believe the bogus bills were printed on the mainland.
Detectives leading the probe have contacted their counterparts across the border to confirm the belief as suspicion grows that their makers are trying to use Hong Kong and Macau as "circulation points" to cash in with the fake notes, which are modelled on the 2003 series of HSBC and Bank of China bills.
A police source said they asked the Public Security Bureau for help because they believed the bills were made outside Hong Kong. He said police were still looking into whether the HSBC and Bank of China copies were made by the same syndicate.
Another source said the fakes seized recently were of better quality than those in the past.
Meanwhile yesterday, officers were called to Nanyang Commercial Bank in Quarry Bay when a 60-year-old man tried to deposit 10 HK$1,000 bills and seven were suspected to be bogus. Police later arrested him and another 51-year-old man. Both were being questioned last night.
The high-quality counterfeits were discovered last week. So far, 97 bogus HK$1,000 bills have been seized, police said. The fakes include the anti-counterfeit features of genuine banknotes.
The Commercial Crime Bureau, which is leading the investigation, has issued guidelines for identifying the fake notes, whose details and colours vary slightly from genuine ones.
In Macau, law enforcers have seized more than 130 bogus HK$1,000 bills of the same type, a large number of which were found in casinos. Hong Kong police are exchanging information with them.
Separately, police arrested a 43-year-old man, his 16-year-old son, and their 19-year-old male relative after they tried to exchange 13 suspected fake 100 yuan banknotes with a moneychanger in Tuen Mun yesterday.