The US government has closed one of its websites that contained documents found during the invasion of Iraq in 2003.
The US website contained details of Iraq's weapons programmes
Weapons experts had complained that the site contained details on making nuclear bombs, the New York Times said.
The US had set up the site to post documents that it hoped might reveal information about Saddam Hussein's weapons programmes.
A US national intelligence spokesman said there would be a careful review before the site went online again.
The website, Iraqi Freedom Document Portal, was set up in March after pressure from Republican legislators that intelligence experts were taking too long to comb through thousands of documents from Saddam Hussein's Iraq.
They wanted public help in sifting through the mass of material.
In the last few weeks, the website had posted accounts of Iraq's secret research into nuclear bomb-making before the 1991 Persian Gulf War, the New York Times said.
The documents reportedly contained detailed information on the radioactive cores of atom bombs and how to build nuclear firing circuits and trigger explosives.
One diplomat told the New York Times that the documents were "a cookbook".
Weapons expert Peter Zimmerman told the newspaper that the website material was "very sensitive, much of it undoubtedly secret restricted data".
US Director of National Intelligence John Negroponte had cautioned against posting the documents before the website went public, a former official said.
''John Negroponte warned us that we don't know what's in these documents, so these are being put out at some risk, and that was a warning that he put out right when they first released the documents,'' former White House chief of staff Andrew Card told NBC television.
The website contained a warning that "the US government has made no determination regarding the authenticity of the documents... or factual accuracy of the information contained therein".
Mr Negroponte's spokesman, Chad Kolton, said in a statement there were "strict criteria" governing what was posted on the website.
"The material currently on the website, as well as the procedures used to post new documents, will be carefully reviewed before the site becomes available again," he said.