Well noted: The Monetary Authority lists ways to identify fake banknotes, and the new security features of the 2003-series notes, on its website.

Police have seized 1,306 fake HSBC $1,000 notes and arrested 25 people for using them since the case first came to light on March 10.

The suspects included one Vietnamese and five two-way permit holders. Seizures of the same counterfeit notes were also reported in Macau.

In a Legislative Council report, Police said the fake notes were likely produced outside Hong Kong, and a dedicated team is investigating. It is exchanging intelligence with authorities in Guangdong, Shenzhen and Macau, and has informed Interpol of the case.

Police and the Monetary Authority will hold 22 seminars for bank staff, money changers and retailers in the next two weeks on how to identify the new counterfeit.

The authority has listed the ways to identify the fake notes, and the new security features of the 2003-series notes, on its website. It urged HSBC to quicken the phasing-out of the old series $1,000 notes, to stem the counterfeit problem and to facilitate detection by bank staff and Police.

The number of counterfeit notes discovered so far represents 0.0015% of the total 87 million $1,000 notes in circulation, or 15 parts per million.