They are but a small detail of the security and surveillance entourage that surrounds Doctor Abdul Qadeer Khan and his every movement, and the house is one of several palatial villas he owns in the capital.

Credited with fathering Pakistan's nuclear bomb, Khan is publicly hailed as a national hero. But enemies deride him as little more than a metallurgist who stole data.

"He's a metallurgist, not a nuclear scientist as widely advertised ... he has certainly not made any outstanding inventions," said Pervez Hoodbhoy, professor of physics at Islamabad's Quaid-e-Azam University.

Now the father of the Islamic world's first nuclear bomb is at the centre of allegations that Pakistan's nuclear expertise was clandestinely sold via black marketeers to a rogues' gallery of states: Iran, Libya and North Korea.

Officials told AFP late Sunday Khan had admitted selling nuclear secrets along with four other officials between 1986 and 1993.

Born in Bhopal, India, Khan was 10 years old when his family migrated by train to Pakistan during the bloody 1947 partition of the sub-continent.

His contribution to Pakistan's nuclear programme was the procurement of a blueprint for uranium centrifuges, which transform uranium into weapons-grade fuel for nuclear fissile material.

He was charged with stealing it from The Netherlands while working for Anglo-Dutch-German nuclear engineering consortium Urenco, and bringing it back to Pakistan in 1976.

On his return, he was put in charge of Pakistan's uranium enrichment project.

By 1978, his team had enriched uranium, and by 1984 they were ready to explode a nuclear device, he told Pakistan's The News daily in a 1998 interview.

The project is credited with ultimately leading to Pakistan's first nuclear test explosion in May 1998.

Khan's aura began to dim in March 2001 when President Pervez Musharraf, reportedly under US pressure, removed him from the chairmanship of KRL and made him special adviser on strategic and KRL affairs.

But Pakistan's nuclear establishment had never expected to see its most revered hero in the dock.

The move was prompted after Islamabad received a letter in November from the International Atomic Energy Agency (IAEA), a UN watchdog, raising claims that Pakistani scientists were the source of sold-off nuclear knowledge.

Hoodbhoy said the accusations against Khan, while yet to be publicly proved, were plausible.

"He's a man who does things for profit. He operates in a milieu where the sharing of such things is not regarded badly," Hoodbhoy told AFP.

Khan and his KRL associates may have traded nuclear information with foreign brokers based in Dubai, another official familiar with KRL said.

"Khan and the group was mostly responsible for bringing resources for Pakistan's nuclear programme from outside, particularly through a Dubai-based group of international brokers," the official told AFP, requesting anonymity.

"While they were dealing with these brokers, the suspicion is that they may have passed on nuclear know-how to these brokers, who then passed it on to Iran and Libya."

Khan himself said in a speech to the Pakistan Institute of National Affairs in 1990 that he had shopped around on world markets while developing Pakistan's nuclear programme.

After the May 1998 tests triggered international sanctions, the sense of anti-Western nationalism among Pakistan's nuclear establishment and the Pakistan Atomic Energy Commission (PAEC) grew, Hoodbhoy said.

"They have, especially over the last decade or so, become much more religious and their attitudes are considerably more anti-Western than 30 years ago," he said.

Khan believed in nuclear defence as the best deterrent. Talking to The News after the 1998 tests, Khan said Pakistan "never wanted to make nuclear weapons. It was forced to do so."

Hoodbhoy said he espoused Islamic nationalism. "He thinks the bomb is essential to protect Islam against assault from those who hate Islam," Hoodbhoy said.

WAR.WIRE