A British newspaper forcefully rejected accusations by WikiLeaks yesterday that it was responsible for more than a quarter of a million secret, unredacted US diplomatic cables being made available on the internet.
The Guardian, which was one of a handful of newspapers worldwide that began publishing redacted versions of the cables last year, described the WikiLeaks's claims as nonsense.
A WikiLeaks spokesman in the US yesterday confirmed that unedited versions of the 251,000 cables, complete with the names of confidential sources, had become generally available.
However, he attempted to deflect criticism by saying The Guardian had been responsible by including a password to its files in a book published seven months ago.
The newspaper has been publishing the cables under an agreement with Julian Assange, the whistle-blowing website's founder.
In a statement, WikiLeaks said: "A Guardian journalist has, in a previously undetected act of gross negligence or malice, and in violation of a signed security agreement with the Guardian's editor-in-chief Alan Rusbridger, disclosed top secret decryption passwords to the entire, unredacted, WikiLeaks Cablegate archive.
"We have already spoken to the [US] state department and commenced pre-litigation action. We will issue a formal statement in due course."
However, responsibility for the leak, which could threaten the lives of hundreds of informants across the world, was furiously rejected by the newspaper.
A spokeswoman for Guardian News & Media said: "It's nonsense to suggest The Guardian's WikiLeaks book has compromised security in any way.
"Our book about WikiLeaks was published last February. It contained a password, but no details of the location of the files and we were told it was a temporary password which would expire and be deleted in a matter of hours.
"It was a meaningless piece of information to anyone except the person or persons who created the database. No concerns were expressed when the book was published and if anyone at WikiLeaks had thought this compromised security, they have had seven months to remove the files.
"That they didn't do so clearly shows the problem was not caused by The Guardian's book."
In its report on the row yesterday, the newspaper said that when it started reproducing redacted versions of the cables last year, WikiLeaks shared the documents through a secure server for a period of hours before taking the server offline and removing the files.
"But unknown to anyone at The Guardian, the same file with the same password was republished later on BitTorrent, a network typically used to distribute films and music," the newspaper reported.
In recent days, after Der Spiegel revealed that the full set of unredacted cables had become available online, WikiLeaks rushed to publish more than 100,000 previously unreleased documents. Some of these also reportedly contained the names of confidential informants.
The US along with other governments and human rights groups have previously warned Mr Assange - who is under house arrest in the UK fighting extradition to Sweden on rape charges, which he denies - that publishing informants' names could endanger their lives.
Now, WikiLeaks is claiming that Guardian investigations editor David Leigh "recklessly, and without gaining our approval, disclosed the decryption passwords" in his book, WikiLeaks: Inside Julian Assange's War on Secrecy.
It said that the newspaper's "disclosure" was a violation of the confidentiality agreement between WikiLeaks and Mr Rusbridger signed on July 30 last year.
Mr Leigh said yesterday that the WikiLeaks's claims were "time-wasting nonsense".
He said that Mr Assange had supplied him with a password needed to access the US embassy cables from a server in July last year, but that Mr Assange had assured him the site would expire within a matter of hours.
Mr Leigh added: "What we published much later in our book was obsolete and harmless. 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.
"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."