Hong Kong is among global tax havens where the super-rich stashed between US$21 trillion (HK$163.8 trillion) and US$32 trillion by the end of 2010.
That is the charge from London- based group Tax Justice Network, which says the amount of wealth tucked away in offshore accounts of the super-rich is larger than previously imagined.
But Ayesha Macpherson Lau, KPMG partner-in-charge for tax in Hong Kong, rejected the "tax haven" report.
She pointed out that the SAR's double-taxation agreements with other governments helps it exchange information on suspected tax evaders.
A government spokeswoman also challenged the report, insisting Hong Kong is not a tax haven as there are no gray areas in its simple taxation structure.
The campaign group's previous estimate of offshore stashes in 2005 was about US$11.5 trillion.
Its estimates are based on sources that include Bank of International Settlements data, interviews with private bankers and wealth industry analysts, and a study of the amount of assets run by the top 50 international private banks.
Among the top 20 developing nations that lost tax revenue overseas, China ranks first with nearly US$1.2 trillion siphoned offshore by 2010.
Next are Russia and South Korea on US$798 billion and US$779 billion missing, respectively.
"Hong Kong and some overseas nations, including Britain, have reached double-taxation agreements so that the authorities can share information on suspected tax evaders," Lau said in rejecting the possibility of the SAR being a tax haven.
And Taxation Institute of Hong Kong president Philip Hung agrees.
"It is really unfair to claim that Hong Kong is a tax haven," he said.
"Because of the low tax rate, simple taxation structure and robust financial system, many overseas investors and businesses have been prompted to transfer their assets and invest in the territory," he said.
"It is wrong to claim that these investors and enterprises have come to Hong Kong because it is a tax haven."
The Financial Services and the Treasury Bureau also dismissed the group's claim. In a statement, it said such accusations are made because those groups "have no clear understanding" on the taxation structure and business environment in Hong Kong.
"Hong Kong has always upheld the work of the international community to enhance taxation transparency," the bureau said, adding the low tax rate exists thanks to prudent government handling of public finances and expenses. TJN claims assets of the super-rich are hidden offshore because "private bankers, haven lawyers and accountants get paid handsomely to hide their clients' assets, identities and even behavioral patterns."
City University economics professor Li Kui-wai had this to say: "Hong Kong is named as a tax haven as overseas investors generally prefer to transfer their assets and make investments here."
"As there is no capital gains or dividend tax in Hong Kong, investors don't need to pay tax when making a profit on their investment in the stock market here," he said.
"Some foreign investors might not report gains generated to evade paying capital gains tax in their home nations."