WikiLeaks, the whistleblowing site set up by Julian Assange, has claimed that it was behind the fake opinion piece circulating on the internet under the name of Bill Keller, columnist and former executive editor of the New York Times.

In a tweet, WikiLeaks said:

The organisation implied that it – or its "great supporters", whomsoever they might be – had carried out the stunt in a bid to embarrass the Times into covering the financial blockade of WikiLeaks by US companies:

Firms such as PayPal, Visa and Mastercard have refused to channel donations to WikiLeaks, saying they cannot support illegal activity. The ban has caused WikiLeaks huge financial problems.

That WikiLeaks should have masterminded the hoax – assuming the group is telling the truth – is not entirely surprising. Assange had a falling out with the New York Times, and its then editor Bill Keller, after the paper published a profile of him that he deemed unflattering (Disclosure: the Guardian also had a falling out with Assange, a while later.)

So there seems to be an element here of old score-settling.

The hoax circulated on Saturday night, and on Sunday morning Keller broke his normal temperate tone and tweeted all in caps to his 40,000 Twitter followers:

The fake in question was a cod Keller op-ed entitled 'WikiLeaks, a Post Postscript'. Visually, it was immaculate – replicating perfectly the typographic style of his column down to the author's photograph, tool kit and Times adverts.

Despite the impressive visuals, Keller himself (the real one) was not impressed. He told the Guardian: "I see this in the realm of childish prank rather than crime against humanity. It's a lame satire. I'd take it a little more seriously if it were actually funny."

Like the topography, the way the column is written was also constructed in such a way as to make it look, at least at first glance, as though it were genuine Keller. In the cod article, "Keller" writes: "I've said repeatedly, in print and in a variety of public forums, that I would regard an attempt to criminalize WikiLeaks' publication of these documents as an attack on all of us."

The sentence is a direct lift from an email that the real Keller sent Mathew Ingram of GigaOM.

Having hooked the reader with genuine Kellerisms, the article then goes on to portray the Times columnist in an unflattering light. It has him say that "journalism should work in unison with government" and opine that had the Times had the WikiLeaks cables to itself (rather than sharing them with the Guardian and other papers), he would have granted the US government the right to review all of the documents before publication.

"My views on WikiLeaks are widely misrepresented," a rather tired (real) Keller said. "This falls ham-handedly in the realm of misrepresentation."

The fake article was distributed through Twitter using a couple of routes. One appeared to be via Keller's own official Twitter feed with the handle @nytkeIler.

A closer look at that feed, though, reveals that the handle @nytkeIler was subtly misspelt to confuse the reader. The apparent two Ls in the middle were in fact spelled with a capital i and a lower case L as in @nytkeiler.

The same ruse was used to post a fake tweet under Keller's name saying "I am now a world expert in dressage. Ask me anything."

The second route was through Keller's genuine Twitter feed. A reference to the fake article by @journalismfest was retweeted under Keller's official name, suggesting that his Twitter feed may have been hacked.

Between the design, the retweeting and the plagiarism, there was enough in the fake article to fool many. Those taken in include New York Times lead tech writer Nick Bilton, who called it an "important piece" in a tweet that he later deleted:

Among many others who fell into the trap were Dan Gillmor, who writes an online column for the Guardian:

Those duped seemed to include the hacker group Anonymous, though it is a moot point whether or not this endorsement of the fake was innocent:

Whoever carried out the hoax appears to have spent quite a while finessing it. The fake Times domain was registered on 30 March.

The New York Times is investigating the scam to see whether its web systems had been compromised and whether there were any legal issues resulting from the copying of its domain format.