Author issues retraction and admits he made a mistake about architect, who has issued writ for defamation

On Monday night, the editor of the New York Review of Books, Robert Silvers, released a statement to the Guardian and then posted it on the magazine's website. It was a letter of regret from Filler in the form of a note to his editors at the magazine.

It reads:

"To the Editors: In my review of Rowan Moore's Why We Build: Power and Desire in Architecture [NYR, 5 June], I quoted comments by the architect Zaha Hadid, who designed the Al Wakrah stadium in Qatar, when she was asked in London in February 2014 about revelations a week earlier in the Guardian that hundreds of migrant labourers had died while working on construction projects in Qatar.

"I wrote that an 'estimated one thousand laborers … have perished while constructing her project thus far'.

"However, work did not begin on the site for the Al Wakrah stadium, until two months after Ms Hadid made those comments; and construction is not scheduled to begin until 2015.

"There have been no worker deaths on the Al Wakrah project and Ms Hadid's comments about Qatar that I quoted in the review had nothing to do with the Al Wakrah site or any of her projects. I regret the error."

Robert Silvers said the magazine was posting the statement on its website independently, not as a result of consultation with Hadid or her lawyers.

"We have done this entirely on our own. This letter contains the facts that should be made public and the regret that we thought was appropriate," he told the Guardian. He declined to discuss monetary damages. He said retractions at the magazine were "very rare".

He said Filler was out of town and not available for comment.

Hadid is being represented in her lawsuit by top New York-based lawyer Oren Warshavsky, well-known for his work on efforts to recover assets defrauded from clients by jailed pyramid-scheme mastermind Bernard Madoff.

Warshavsky issued a statement saying: "The decision to file a lawsuit is never one made lightly. Ms Hadid carefully considered the issues at stake to her professional career and reputation and came to the conclusion that the filing of the lawsuit was the correct action to take.

"We are in receipt of Mr Filler's retraction issued today and aware of the New York Review of Books' plan to post it on their website. Ms Hadid together with counsel are reviewing it now and will respond after further careful consideration."

Sources said no decision had been made about damages.