Mossad had 'six hours to break into Iranian nuclear facility'

New details have emerged of how the Israeli spy agency Mossad smuggled out Iranian nuclear documents earlier this year.

The New York Times released a report on Sunday which revealed that Israeli agents had just six hours and 29 minutes to break into the non-descript nuclear facility in a commercial district of the Iranian capital, Tehran, before the guards arrived in the morning.

In that time, they infiltrated the facility, disabled alarms, and cut through safes to remove the secret documents before leaving undetected.

It added certain documents appeared to demonstrate that Iran had worked to "systematically assemble everything it needed to produce atomic weapons", but noted that exculpatory information could have been left out of the hand-picked documents shown to its reporter.

The Washington Post reported that Iran "was as on the cusp of mastering key bomb-making technologies" when the programme ended last decade.

The information reported on Sunday shed more light on the notorious Mossad operation but offered few other details beyond what Prime Minister Binyamin Netanyahu claimed in April, when he unveiled what he said was a trove of secret Iranian nuclear documents dating back to 2003 snatched by Israeli intelligence.

Netanyahu argued that the 55,000 pages of documents and 183 CDs of the Iranian programme dubbed "Project Amad" gave further justification for US President Donald Trump to withdraw from the Iran nuclear deal with world powers.

Iran hit back at Tel Aviv, saying entire document trove is fraudulent.

There was no immediate comment from Netanyahu's office.