Unease over a clandestine US data collection program has rippled across the Pacific to two of Washington's major allies, Australia and New Zealand, raising concerns about whether they have cooperated with secret electronic data mining.

Both Canberra and Wellington share intelligence with the United States, as well as Britain and Canada. But both Pacific neighbors now face awkward questions about a US digital surveillance program that Washington says is aimed primarily at foreigners.

In Australia, the conservative opposition said it was "very troubled" by America's so-called PRISM program, which newspaper reports say is a top-secret authorization for the US National Security Agency (NSA) to extract personal data from the computers of major Internet firms.

The opposition said it was concerned that data stored by Australians in the computer servers of US Internet giants like Facebook and Google could be accessed by the NSA, echoing fears voiced in Europe last week over the reach of US digital surveillance in the age of cloud computing.

Australia's influential Greens party called on the government to clarify whether Canberra's own agencies had access to NSA-gathered data, which according to Britain's Guardian newspaper included search history, emails, file transfers and live chats.

"We'll examine carefully any implications in what has emerged for the security and privacy of Australians," Australia's Foreign Minister Bob Carr said in an interview yesterday, when asked whether Canberra had cooperated with Washington's secret initiative.

Both countries are members of the so-called "five eyes" collective of major Western powers collecting and sharing signals intelligence, set up in the post-war 1940s.

In New Zealand, Internet file-sharing tycoon Kim Dotcom, who is fighting extradition to the United States on charges of online piracy, took to Twitter yesterday to highlight what he called the role of NSA surveillance in his case, and the cooperation of New Zealand's spy agency.

Doctom accusation

"The New Zealand GCSB spy agency was used to spy on my family because all surveillance was available to American agencies in real time," he tweeted, citing the Government Communications and Security Bureau.

"My case against the spy agency in New Zealand will show the degree of cooperation with the NSA."

When asked if the GCSB cooperated with the NSA program, a New Zealand government spokeswoman said, "We do not comment on security and intelligence matters. New Zealand's intelligence agencies are subject to an oversight regime, which we are looking to strengthen ..."

A New Zealand watchdog in September found that the GCSB had illegally spied on Dotcom, founder of file-sharing site Megaupload, intercepting his communications ahead of a raid on his home in 2012 by New Zealand police, acting on a request from the US Federal Bureau of Investigation. The raid was ruled invalid.