A 65 per cent jump in counterfeit bank note seizures last year may have been fuelled by mainland visitors bringing in fake dollar bills. Police figures revealed 5,177 notes of all denominations were seized last year, up from 3,137 in 1996. Last year's figure was the highest for 10 years. Detectives from the Commercial Crime Bureau (CCB) counterfeit and forgery investigation unit said the figure was a 'drop in the ocean' compared with the overall note supply which amounts to $84 billion. But they voiced concern at the increasing quality of the notes. CCB Bureau Superintendent Ken Reed said: 'Of all the resources we put into counterfeiting . . . counterfeit currency is the one we concentrate on most. 'Undermining the integrity of a currency is very dangerous and if the quality gets better there will be some problems.' Mr Reed said almost all counterfeit local currency notes in circulation were found eventually, largely due to their poor quality and alert bank staff. Among the notes seized last year were 1,657 Hongkong Bank $1,000 notes and 1,102 Standard Chartered Bank $100 notes. There have been no cases of forged Bank of China notes. It is believed most of the fake currency is made in China and possibly Taiwan. There is no evidence of production in the SAR. CCB Chief Inspector Michael Yu Shi-cheung said there had been a drop in the number of forged $10 coins. Police intelligence reports show counterfeit note sellers place as much as a 30 per cent mark-up on each bill.