Prime Minister Abdullah Ahmad Badawi, whose son was embroiled in the scandal, told reporters the International Atomic Energy Agency (IAEA) was in talks with Malaysian security authorities over questioning the agent, Sri Lankan businessman B.S.A. Tahir.

But he would not say whether they would be given permission. "I do not want to give assurances of something which is a subject of discussion between the concerned authorities," he said.

Abdullah, who is also the internal security minister, said he would leave it to the Malaysian security authorities to decide.

Tahir was arrested last week under the Internal Security Act (ISA), which allows indefinite detention without trial and is being held at the Kemunting detention centre in the northern Perak state.

He was described by US President George W. Bush earlier this year as the "chief financial officer and money launderer" for Khan, who has admitted selling nuclear secrets abroad but has been pardoned by President Pervez Musharraf.

Washington hailed the arrest of Tahir, saying it could be a breakthrough in global efforts to dismantle Khan's nuclear network.

But Malaysia said last week it would not allow officers from the US Federal Bureau of Invetigation (FBI) to question the detainee, saying it did not need "foreign intervention".

Asked whether Malaysia would share information extracted from Tahir with the United States, Deputy Internal Security Minister Noh Omar said: "There is no need, but if they ask, we will have to see."

The scandal embroiled Abdullah's son, Kamaluddin, when it was revealed that a company he owned, Scomi Precision Engineering (SCOPE), had manufactured centrifuge parts seized on a ship headed for Libya last year.

A police probe cleared the company, which said it had been misled about the purpose and destination of the parts, allegedly ordered by Tahir on behalf of Pakistan's Khan.

Tahir, 44, admitted to police that he acted as a middleman for Khan, and gave a detailed insider's view of the proliferation scandal, according to an official report handed to the IAEA in February.

Tahir said Khan asked him to send centrifuges, which can be used to enrich uranium for nuclear weapons, to Iran in 1994 or 1995 and had told him that an undisclosed amount of enriched uranium was sent by air from Pakistan to Libya around 2001.

WAR.WIRE