The government's privacy watchdog is investigating whether the freedom of New Zealanders was breached by a US Government spying programme.
Millions of financial transactions made by Kiwi citizens and companies could have been searched by the US, which claims the monitoring is to counter terrorism.
The Privacy Commissioner said the
inquiry was being treated "very carefully" and that it could involve the banking details of a large number of New Zealanders.
The New York Times revealed last month that CIA agents and US Treasury officials were secretly monitoring transactions handled by the Society for Worldwide Interbank Financial Telecommunications (Swift).
The industry-owned co-operative connects nearly 7900 financial institutions in 204 countries - including ASB Bank, Kiwibank, Westpac, and ANZ/National Bank.
The Bush administration has defended the programme as a potent weapon in its war on terror and criticised the media for publicising it.
Swift's 2005 annual report says about 13.6 million "messages" from New Zealand were sent or received through the network last year.
Green MP Keith Locke this week lodged a complaint with the Privacy Commissioner, following complaints laid here and in 32 other countries by a London-based watchdog.
Five banks and 16 other financial institutions use Swift here.
The system allows banks to send encoded messages to banks overseas. The majority of "messages" are money transfers, although some simply contained information.
Examples of transactions that would go through Swift include foreign exchange payments between banks, depositing money in a friend or family member's overseas account, and companies engaging in international trade. Credit card transactions are not included.
Locke said our government should stop "looking the other way" out of deference to the US.
"We should protect New Zealanders' interests wherever they are," he said.
"We're interested at the moment in what's happening to New Zealanders in Lebanon, for example. Aren't we also protectors of the financial interests of New Zealanders living in New Zealand?"
Privacy Commissioner Marie Shroff said her office would be actively investigating whether New Zealanders' financial information had been inappropriately disclosed.
