The International Atomic Energy Agency is to further probe Libya's two-decades-long quest to develop nuclear weapons as questions linger about highly enriched uranium particles found in the north African state and a global black market, according to a confidential IAEA report released to diplomats in Vienna Friday.

Libya's revelations to the IAEA continue to tell as much about other countries as about Tripoli's activities, diplomats and experts said.

The report is to be submitted to a meeting of the 35-nation IAEA board of governors that opens in Vienna on June 14 and at which IAEA chief Mohamed ElBaradei had said in February that he hoped to close the Libyan dossier.

The IAEA, the UN organization that verifies adherence to non-proliferation safeguards, has been overseeing Libya's disarmament, which Tripoli agreed to last December 19 with the United States and Britain.

Turkey is now seen as a source of centrifuge parts shipped to Libya's nuclear weapons program, diplomats said over the weekend.

While Libya had agreed in December to dismantle its weapons of mass destruction programs, in March a container of components for sophisticated L-2 centrifuges used to enrich uranium up to bomb-grade levels arrived by boat in Libya, the IAEA said in its report.

The container had "escaped the attention" of the US-led teams which had seized five containers of centrifuge parts from "the cargo ship BBC China in October 2003," the IAEA said.

A senior diplomat close to the IAEA told AFP the agency was investigating parts that had been manufactured in Turkey and that this might be the shipment that had arrived in March.

The diplomat confirmed a report in The Washington Post Saturday, which was sourced to US intelligence officials, that an important quantity of nuclear equipment secretly purchased by Libya appears to be missing.

The diplomat said the IAEA was "still looking and knows it should have more equipment" in hand based on what Libya has said.

He said equipment "could still be in manufacturers' workshops" or even be en route somewhere.

Libya, along with Iran and North Korea, was clandestinely supplied nuclear technology and parts by the international smuggling network run by Pakistani scientist Abdul Qadeer Khan, the man considered the father of Pakistan's atomic bomb.

Khan built an elaborate international network for manufacturing, assembling and shipping atomic equipment, especially parts for high-technology centrifuges, the instrument for making the highly enriched uranium (HEU) used in atom bombs.

Khan's network had a manufacturing firm in Malaysia and used the United Arab Emirates as a shipping point.

Diplomats in Vienna named Turkey as both an assembly and manufacturing point, and said the UAE was also used for assembly of parts.

One diplomat said details were emerging slowly since the Libyans "had for more than 20 years run their nuclear program in secrecy and now all of a sudden they have to talk to foreigners. It's like a change of regime."

Meanwhile, IAEA inspectors have found contamination from HEU as well as low enriched uranium on gas centrifuge equipment in Libya, the report said.

This is similar to HEU contamination that has been found in Iran on centrifuge parts.

Non-proliferation expert Gary Samore told AFP from the International Institute for Strategic Studies in London that in Libya this was almost certainly from "contaminated parts bought from Pakistan."

But as Iran wants to maintain its uranium enrichment capability, investigators are wondering if the HEU particles found there are signs of Iranian-done enrichment rather than contamination from clandestine imports.

WAR.WIRE