The man who for two years led Iran's nuclear negotiations has laid out in unprecedented detail how the regime took advantage of talks with Britain, France and Germany to forge ahead with its secret atomic programme.
In a speech to a closed meeting of leading Islamic clerics and academics, Hassan Rowhani, who headed talks with the so-called EU3 until last year, revealed how Teheran played for time and tried to dupe the West after its secret nuclear programme was uncovered by the Iranian opposition in 2002.
He boasted that while talks were taking place in Teheran, Iran was able to complete the installation of equipment for conversion of yellowcake - a key stage in the nuclear fuel process - at its Isfahan plant but at the same time convince European diplomats that nothing was afoot.
"From the outset, the Americans kept telling the Europeans, 'The Iranians are lying and deceiving you and they have not told you everything.' The Europeans used to respond, 'We trust them'," he said.
Revelation of Mr Rowhani's remarks comes at an awkward moment for the Iranian government, ahead of a meeting tomorrow of the United Nations atomic watchdog, which must make a fresh assessment of Iran's banned nuclear operations.
[Little Green Footballs]