Anti-secrecy group WikiLeaks said Thursday that its massive archive of unredacted U.S. State Department cables had been exposed in a security breach which it blamed on its one-time partner, Britain's Guardian newspaper.
In a 1,600-word-long editorial posted to the Internet, WikiLeaks accused the Guardian's investigative reporter David Leigh of divulging the password needed to decrypt the files in a book he and another Guardian journalist, Luke Harding, published earlier this year.
WikiLeaks said the disclosure had jeopardized the "careful work" it was doing to redact and publish the cables.
"Revolutions and reforms are in danger of being lost as the unpublished cables spread to intelligence contractors and governments before the public," WikiLeaks said in its statement.
Leigh and the Guardian both denied wrongdoing, and the exact sequence of events WikiLeaks was referring to remained clouded in confusion.
It has long been known that WikiLeaks lost control of the cables even before they were published. One copy of the secret documents leaked to The New York Times in the fall of 2010, and other media organizations, including The Associated Press, have since received copies independently of the self-proclaimed online whistleblower.
The AP has independently confirmed that the cables are now circulating on the Internet.
In comments to the AP, Leigh dismissed WikiLeaks' claims as "time-wasting nonsense."
He said that WikiLeaks founder Julian Assange had supplied him with a password needed to access the U.S. embassy cables from a server back in July of 2010 _ but that Assange assured him the site would expire within a matter of hours.
"What we published much later in our book was obsolete and harmless," Leigh said. "We did not disclose the URL (web address) where the file was located, and in any event, Assange had told us it would no longer exist."
Leigh added that "I don't see how a member of the public could access such a file anyway, unless a WikiLeaks or ex-WikiLeaks person tells them where it is located and what the file was called."
Repeated attempts to reach WikiLeaks staffers for an explanation of where the file was left and how it got online were unsuccessful, although on its Twitter feed the group described one of Leigh's previous statements as false and warned of "continuous lies to come."
To add to the intrigue, WikiLeaks asked its 1 million or so followers to download a large coded file which it said it would decrypt at a later point. Then it threatened to post the entire unredacted archive of State Department documents immediately.
Past disclosures already drawn from WikiLeaks' trove of embassy cables have infuriated and humiliated high-ranking officials across the world, with the U.S. ambassador to Mexico losing his job over the revelations.
WikiLeaks says the cables' release also played a role in setting off the mass movement that has jolted dictatorial regimes across the Arab world.
But American officials have warned that the disclosures could also have serious consequences for informants, activists and others quoted in the cables.
"What we have said all along about the danger of these types of things is reinforced by the fact that there are now documents out there in unredacted form containing the names of individuals whose lives are at risk because they are named," Defense Department Col. Dave Lapan said Wednesday, before the full scale of the issue became known.
"Once WikiLeaks has these documents in its possession, it loses control and information gets out whether they intend (it) to or not," Lapan told Pentagon reporters.
In its statement Thursday, WikiLeaks claimed that it had tried to warn the State Department about what was about to happen. The State Department did not immediately respond to a call seeking comment.
Pauline Jelinek in Washington and Jonathan Stray in New York contributed to this report.