"I trust, I hope that this was the last time that something would come trickling down again from their past activities," ElBaradei said in an interview with the BBC's Newsnight programme.

"Large or small, it's important that they declare everything to build the confidence," he said.

The IAEA said late last month that Iran had failed to report possibly weapons-related atomic activities despite promising full disclosure.

It said Tehran had not told the IAEA it had designs for sophisticated "P-2" centrifuges for enriching uranium, nor that it had produced polonium-210, an element which the agency said could be used as a "neutron initiator (to start the chain reaction) in some designs of nuclear weapons."

ElBaradei told the BBC he "would not have conceived" proliferation on the scale that emerged in February when Pakistan's Abdul Qadeer Khan admitted supplying nuclear technology to Iran, Libya and North Korea.

"I think it is coming as a total shock to pretty much everybody," he said.

"It was really beyond anybody's imagination, at least beyond my imagination, that this -- such a sophisticated complex network of black markets in nuclear facilities, in even bomb design -- has been going on underground," he said.

It was "still an open question" whether other countries had acquired nuclear equipment or knowledge, ElBaradei said.

"We need national laws to criminalise any effort by any individual or companies that aim to illicitly traffic in equipment or material that could lead to nuclear weapons proliferation," he said.

As for Libya, which late last year decided to abandon all weapons of mass destruction programmes, ElBaradei was in no doubt that it was only a matter of time before they developed a nuclear weapon.

The IAEA chief said the Iraq war had benefited his work because it showed that the country had been effectively disarmed through inspection, and people now realised he needed more time to do his job.

"I think maybe the positive message that came out of Iraq maybe was that the international community will not tolerate proliferation of weapons of mass destruction," he said.

In the wake of spying accusations levelled against Washington and London, ElBaradei said he took it for granted that he had been bugged.

"It doesn't make you feel good because there is an invasion of privacy clearly," he said.

WAR.WIRE