A retired US general, James Cartwright, is the target of a Justice Department investigation into the leaking of secret information about the Stuxnet virus attack on Iranian nuclear facilities in 2010, NBC News reported on Thursday, citing unidentified legal sources.

NBC said Cartwright, once the second highest ranking officer in the US military, was being investigated over the leaked information about the computer virus, which temporarily disabled 1,000 centrifuges used by Iran to enrich uranium, setting back its nuclear programme.

A "target" is someone a prosecutor or grand jury has substantial evidence linking to a crime and who is likely to be charged.

The Justice Department referred questions to the US attorney's office in Baltimore, where a spokeswoman, Marcia Murphy, declined to comment.

The New York Times published a detailed account of the Stuxnet program in June last year, in which it said President Barack Obama had decided to accelerate US cyber attacks, which began under George W Bush.

The story was based on 18 months of interviews with "current and former American, European and Israeli officials involved in the program, as well as a range of outside experts", the Times said in its story.

Cartwright, a four-star general who is now retired, was vice-chairman of the joint chiefs of staff from 2007 to 2011. The Times reported that he was a crucial player in the cyber operation called Olympic Games, started under Bush.

Bush reportedly advised Obama to preserve Olympic Games. According to the Times, Obama ordered the cyberattacks to be accelerated, and in 2010 an attack using a computer virus called Stuxnet temporarily disabled 1,000 centrifuges that the Iranians were using to enrich uranium.

Congressional leaders demanded a criminal investigation into who leaked the information, and Obama said he had zero tolerance for such leaks. Republicans said senior administration officials had leaked the details to bolster the president's national security credentials during the 2012 campaign.

The Times said Cartwright was one of the crucial players who had to break the news to Obama and vice-president Joe Biden that Stuxnet had escaped onto the internet.

An element of the program accidentally became public in the summer of 2010 because of a programming error that allowed it to escape Iran's Natanz plant and sent it out on the internet, the Times reported. After the worm escaped, top administration officials met to consider whether the program had been fatally compromised.

Obama asked if the program should continue, and after hearing the advice of top advisers, decided to proceed.

The US and other Western countries believe the Iranian nuclear enrichment programme is aimed at building atomic weapons, while Tehran says it is solely for civilian energy purposes.