Staff at an exclusive hotel were among 13 people arrested by the ICAC yesterday in a crackdown over a $5 million counterfeit credit card scam. They had been recruited by a crime syndicate and bribed to pass on details of wealthy guests at the five-star hotel, investigators said. Dozens of forged credit cards are still in circulation, but 187 cards have already been seized by the Independent Commission Against Corruption. Principal investigator Neil Maloney said hotel staff were not the syndicate's only targets. The other people arrested worked in a karaoke bar, a hair salon, or were involved in making or using the counterfeit cards. Senior investigator Cheung Yiu-kei said information from the genuine credit cardholders was simply copied by the hotel and retail staff. Each set of details would be sold for between $300 and $1,000 to other syndicate members who manufactured the cards. Sophisticated equipment that has now been seized by the ICAC could produce the counterfeits in as little as 10 minutes. The syndicate also had links in China, Macau, Taiwan and Malaysia where the forged cards could be used. Mr Maloney said there was a potential for losses of up to $5 million, but so far investigators were aware of the theft of only $500,000. Esmond Chan, vice-president of the MasterCard International security and risk department, said it was impossible for cardholders to prevent details from being stolen. 'Cardholders should keep an eye on their cards during the transaction. 'If their cards are taken away for a long time, they should start following up on what is going on. 'Forgery is always a problem. It's a matter of minimising the risks,' he said. He advised cardholders to check their monthly statements to see whether there were any invalid transactions. Four of those arrested have been released on ICAC bail and the rest are still in custody. The operation, which started in November last year, is still continuing, and one or two more arrests are expected.