President Pervez Musharraf swiftly pardoned Khan, who remains a national hero in Pakistan.

But the extent of Khan's nuclear sales network, which Western diplomats told Reuters made the Pakistani scientist and others extremely wealthy, is only beginning to become clear.

At least half a dozen individuals - most likely without the knowledge of their governments - helped Khan sell technology to Libya, which admitted in December to having a covert nuclear weapons programme, and Iran, which Washington suspects of having a weapons programme similar to Libya's.

Vienna-based diplomats said the list of countries the middlemen come from and where they tried to get atomic technology on behalf of Libya or Iran gets longer by the day.

It includes Germany, the Netherlands, Belgium, South Africa, Japan, Dubai, Malaysia, the United States and elsewhere in Europe and Asia.It also includes Russia, China and Pakistan.

"Other countries will join that list," said one diplomat. "They (the middlemen) were fishing in many different countries for dual-use technology, countries with high-tech industries. A lot of this technology might have been seemingly innocuous."

Dual-use technology can be used either for a civilian nuclear programme or for military purposes.

MIDDLEMEN: SLIPPERY BUT CLEVER

Germany's Sueddeutsche Zeitung newspaper reported earlier this week that three Germans acted as middlemen, one of whom was a businessman and engineer who moved to Switzerland a few years ago and is suspected of helping Iraq, Libya and Iran.

Another middleman - one who diplomats say was instrumental in fingering Khan as a key player in the nuclear black market - was a Sri Lankan businessman operating out of Dubai in the United Arab Emirates.

The nearly 40 countries in the Nuclear Suppliers Group require export licenses to export such technology. The middlemen got licenses by obfuscating the end users' identities.

"A lot of bits and pieces had been produced in different countries," International Atomic Energy Agency (IAEA) chief Mohamed ElBaradei, who is leading the investigation into the nuclear black market, told reporters on Thursday.

ElBaradei also called Khan the "tip of an iceberg" in the global nuclear black market, albeit one of its key players.

But Khan may have been the one orchestrating the movements of the middlemen. "Someone had a plan and was overseeing all this," a diplomat said.

Diplomats said the middlemen bought up bits and pieces of seemingly innocent technology from many different countries in order to avoid raising uncomfortable questions about what the machinery was intended for.

One example was a Malaysian factory that thought it was making oil and gas equipment but which diplomats said made enrichment centrifuge parts for Libya ordered by the Dubai middleman.

With the aid of front companies and bogus but credible cover stories for export license applications, the middlemen were so successful that they enabled Iran to build up a functional programme to enrich uranium without the knowledge of the IAEA or Western intelligence agencies and governments, diplomats said.

Washington says Iran's enrichment programme is at the heart of a covert atom bomb programme, a charge Iran denies.

Diplomats said it was very likely other countries had been customers of Khan and that the full story has yet to be told.

The United States has long suggested Syria was interested in nuclear weapons, and a senior Israeli defence official told Reuters Israel would have expected Saudi Arabia to be on the list, though its name had not yet come up.

(Additional reporting by Dan Williams in Jerusalem)