Intelligence agencies and nuclear inspectors are racing to close a vast international nuclear "supermarket" that has secretly supplied Iran, Libya, North Korea and perhaps several other countries for more than a decade.

	Gen Pervaiz Musharraf

The extent of the Pakistan-based network became clear last night as a leading United Nations official said there was still an urgent need to "dry up the source".

The "supermarket", run by Abdul Qadeer Khan, the father of the Pakistani bomb, was "the most dangerous phenomenon in proliferation for many years," said Mohammed ElBaradei, the head of the International Atomic Energy Agency, the UN's nuclear watchdog.

"This is an area where we cannot act alone. We need the co-operation of intelligence agencies and governments. I expect everybody to chip in."

Despite Khan's confession that he was at the center of the operation, few believe that the uncovering of the network will stop the lucrative black market in nuclear designs, technology and components.

	Abdul Qadeer Khan on Pakistani TV apologizing to the nation

Western intelligence agencies face alarming uncertainties. Are similar networks in operation? What other countries have already bought Pakistani nuclear technology?

American sources said there were "suspicions" that Syria or Saudi Arabia were clients of Khan's network. They said Iran appeared to have bought more technology than it had declared.

Mr ElBaradei said: "Mr Khan is the tip of the iceberg. His confession raises more questions than it answers.

"A lot of other people are involved. Items were made in one country, assembled in others and shipped on false [certificates]."

India's Prithvi missile, capable of carrying a one-ton nuclear  warhead

Middlemen bought parts from half a dozen countries: Japan, Malaysia, South Africa, Germany and at least two other European countries.

The components were ostensibly meant for industrial purposes but were then assembled to make gas centrifuges to enrich uranium for atomic bomb-making. Experts compared the process to selling designs for a kit car and providing help in buying the parts around the world.

George Tenet, the director of the CIA, said the credit for uncovering the network belonged to his organization and MI6, using old-fashioned espionage techniques.

The mountain disintegrates during Pakistan's first official nuclear weapon test.

"First we discovered the extent of the hidden network," he said. "We tagged the proliferators. We detected the network stretching across four continents offering its wares to countries such as North Korea and Iran.

"Working with our British colleagues, we pieced together the picture of the network, revealing its subsidiaries, client lists, front companies, agents and manufacturing plants on three continents."

Despite the growing scale of the revelations, Pervaiz Musharraf, the Pakistani president, pardoned Khan yesterday after his public confession to "unauthorized proliferation activities".

Islamabad declared the scandal over, sticking to its claim that Khan had acted on his own, rather than with Pakistani military co-operation, as is widely suspected.

Gen Musharraf said he would not hand any documents about the scandal to UN inspectors.

Indian Nuclear Test Craters The above and zoomed below images depict the Shakti-1 test, which is presumably one of the pair of multi-kiloton tests conducted on May 11, 1998. India claimed that the yields of these two tests were 45kt and 15kt, although other analysts have suggested that the actual yields were as low as a third these values. It is not evident which of these two tests was given the "Shakti-1" designator, though conventionally this designator has been applied to the higher yield test.

"This is a sovereign country," he said. "No documents will be given. No independent investigation will take place here."

Washington and London have given strong indications that they are prepared to let the matter rest after behind-the-scenes pressure on the Pakistanis to come clean.

Nuclear experts say that Khan made millions of pounds by selling know-how for the equipment needed to make weapons-grade fissile material and the manufacture of nuclear bombs.

He may also have provided some kind of after sales service by giving technical help to build centrifuges.

UN inspectors came across the first concrete reference to his trade in the mid-1990s in Iraq. They found a 1990 memorandum reporting an approach by a man named "Malik" who was relaying an offer from Khan to sell a nuclear bomb design and centrifuge parts for $5 million.

The Iraqis declined the offer, suspecting it was a scam or a trap.