WASHINGTON, Feb 12: Contrary to global fears, there is no evidence the father of Pakistan's nuclear bomb sold nuclear technology to al Qaeda or any other militant group, Pakistan's ambassador to Washington said on Friday.

The network of nuclear scientist Abdul Qadeer Khan, who admitted last year that he leaked nuclear secrets to Iran, Libya and North Korea, was no longer operating and its Pakistani elements had been wiped out, ambassador Jehangir Karamat said in an interview with Reuters.

However, some of Dr Khan's international associates might still be doing illicit business abroad.

He also said that even through Pakistan had no idea where to find al Qaeda leader Osama bin Laden or his deputy Ayman al Zawahri, the Pakistani government had broken the back of Al Qaeda's presence in the country.

An estimated 80 to 100 low-level operatives remained in remote areas of Pakistan, rudderless, eviscerated and on the run, he said.

Asked whether Dr Khan had passed on nuclear secrets to militant groups, Mr Karamat said: "I know for a fact that there is no evidence whatsoever for his ever having done business with Al Qaeda or with any other terrorist organization."

Dr Khan's network, he said, "is gone now. It's history."

"I'm positive that the network has ceased to operate. There may be people internationally who are underground and who in fact may be getting away with something while the focus remains on something which has been closed down," he said.

He said he did not know where or who these associates were, but said Pakistan was working with the United States and had given Washington all the information it had to ensure the network "doesn't spring up again."

Pakistan has never allowed the United States to interview Dr Khan directly, and many experts believe that leaves a huge gap in what can be authoritatively known about the network.

Turning to Al Qaeda, the ambassador said Pakistani law enforcement and military operations in cities and the rugged border region with Afghanistan had led to the capture or killing of 600-650 fairly high-level Al Qaeda leaders, including planners, organizers and financiers, since the Sept 11, 2001, attacks.

"I don't think there are any more of those kind of leadership people in our urban areas," he said. In the border region, "there are no sanctuaries now whatsoever. And if there are any 80-100 estimated people, they are now on the run and looking for places to hide."

Mr Karamat added: "I don't think we should be looking at any resurgence of that kind of activity in the future."

Asked if Pakistan was closing in on Osama, he said: "As far as Osama bin laden is concerned, I couldn't tell you where he is. ... There's never been a sighting of this man who would be a head taller than anybody else in that area. And there's never even been a confirmed rumour or indication, in spite of all the interrogations that have been carried out, about where he is."

"If he is in that area, some remote part of Afghanistan or Pakistan, then he is probably confined to a house or a compound and he's not moving out from there," he said.