The US-based International Consortium of Investigative Journalists has refused to give government agencies access to more than 2.5 million documents revealing secret bank accounts belonging to high-profile, powerful people around the world.
Many accounts are linked to wealthy residents from the mainland, Hong Kong and Taiwan, with assets hidden in a complex web of shell companies in tax havens such as the Caymans and British Virgin Islands.
The centre's director, Australian investigative reporter Gerard Ryle, said that Germany, Greece, South Korea, Canada and the US have asked to look at the treasure trove of data.
"We are declining to do so," Ryle said in a blog post. "The ICIJ is not an arm of law enforcement and is not an agent of the government. We are an independent reporting organisation …."
The group leaked the financial secrets of more than 120,000 offshore companies last week in a move billed as the biggest information leak in recent history and 160 times bigger, in raw data size, than Wikileaks' 2010 release of US State Department cables.
Those who have been named so far include French President Francois Hollande's personal friend and campaign treasurer, Jean-Jacques Augier, Maria Imelda Marcos Manotoc, governor of a Philippine province and daughter of late dictator Ferdinand Marcos, as well as Mongolian politicians.
The ICIJ was established in 1997 to investigate cross-border crime and corruption. It said its findings revealed how the mega-rich used complex offshore structures to own mansions, yachts, art and other assets, gaining tax advantages and anonymity denied the average person.
Ryle said it would run a series of stories over the next fortnight.
Last night the Financial Services and Treasury Bureau said: "The Inland Revenue Department has taken note of the recent release of offshore records by the International Consortium of Investigative Journalists.
"As always, the department will not comment on individual cases and will not disclose the course of action on any information obtained or received due to the secrecy provisions of the Inland Revenue Ordinance."