After months of denial, Pakistan admitted that "rogue scientists" driven by "ambition or greed'' may have been behind secret transferred nuclear technology to Iran, but added that this was without the knowledge of the government.

Sources in Islamabad said Wednesday that the arrest of Khan and Mohammad Farooq, another nuclear scientist took place after Tehran provided the Vienna-based International Atomic Energy Agency (IAEA) a list of atomic experts and countries in Asia, Europe and North America that helped Iran’s ongoing nuclear programmes, including sale of second hand centrifuges used in uranium enriching activities.

So far, there had been no official comments from Iran, that signed officially last week the Additional Protocol to the Non Proliferation Treaty, thus opening up all its atomic-related projects, installations and sites to unrestricted inspections by the United Nations international nuclear watchdog.

"Pakistan has never transferred nuclear technologies and know how to Iran. Pakistan is a nuclear power aware of its responsibilities. We have very stiff control on our nuclear chain of command as well as on the import and export of nuclear materials", Mas’ood Khan, Islamabad’s Foreign Affairs Ministry spokesman Mas’ood Khan told the Persian service of the BBC.

However, he confirmed that Iran, after accepting IAEA’s conditions for signing the Protocol, submitted an extensive list of scientists and nations that cooperated in Iranian nuclear projects.

Former lieutenant general Kamal Matinuddin said he had doubts about the reports from Iran and

Pakistan's Foreign Affairs Minister Riaz A. Khokhar told Pakistani the politicians that two senior scientists were being debriefed under international pressure resulting from appearance of their names in "baseless stories" in the international media, Pakistan's pro-government newspaper "Dawn" reported Wednesday.

Mas’ood Khan said Pakistan is cooperating closely with the IAEA after the agency's inspections of Iranian nuclear facilities showed that Pakistani, European and North American experts had acted as "intermediaries, black marketers" or collaborated with the Iranians in nuclear field.

But some Pakistani defence experts demanded a full public investigation into allegations that Pakistani scientists may have sold sensitive nuclear secrets to Iran.

"It should be thoroughly probed how our scientists, who are trusted so well and watched so closely, are named", former air marshal Ayaz Ahmad said Wednesday.

"We should get into the bottom of the issue and the enquiry report should be made public. When we make a mistake we better acknowledge it", he told the French news agency AFP.

According to IAEA, the Islamic Republic started enriching uranium; a vital process for building atomic weapon, some 19 years ago by importing secretly used centrifuges, possibly from Pakistan, China and North Korea, without ever informing IAEA.

Experts with the IAEA say the centrifuge designs used by Iran were of a machine made by the plant in the Netherlands.

In 1983, after his return to Pakistan, Khan was sentenced in absentia to four years' jail by an Amsterdam court for attempted espionage, a decision later overturned on appeal.

Earlier this year, Washington announced commercial sanctions on Khan Research Laboratories for allegedly arranging the transfer of nuclear-capable missiles from North Korea to Pakistan, a decision Islamabad protested.

"He is too eminent a scientist to undergo a normal debriefing session", the official was quoted by the British news agency "Reuters" as having said.

Khan’s daughter, quoted by the press, expressed deep concern on the fate of his father and blamed Pakistan authorities to gave "sacrificed" his father for their collaboration with the Islamic Republic of Iran.

Tehran was caught "red handed" after IAEA inspectors found used uranium in samples taken in areas in central Iran, where the regime has built secretly a huge plant for enriching uranium.

British newspapers added Wednesday that agents from the United States Federal Bureau of Investigation (FBI) are also taking part in the interrogations, adding that two others, Mohammad Farooq, and another identified only as Sa’id, were "still undergoing debriefing".

But Khan discounted the reports, saying no foreigner or foreign agency was associated.

The White House said Pakistan’s strongman General Parviz Mosharraf has assured the United States that Pakistan is not currently offering technology related to weapons of mass destruction to Libya and Iran.