LONDON, Feb 12: It remains unknown precisely how far nuclear technology was spread by a smuggling ring led by scientist Abdul Qadeer Khan, British Foreign Minister Jack Straw said on Thursday.

Mr Khan, the architect of Pakistan's nuclear weapons programme, had been willing to sell nuclear secrets "to anybody who could pay his price", Mr Straw told a joint press conference in London with NATO Secretary-General Jaap de Hoop Scheffer.

Mr Straw was speaking a day after US President George W. Bush sought global support for tighter curbs on nuclear know-how. Mr Khan publicly admitted last week to leaking nuclear secrets to Iran, Libya and North Korea. He asked for forgiveness and was pardoned by President Pervez Musharraf.

"We don't still know the full scale of the activity. But as President Bush explained in his speech last night, what we had here was somebody who had made a bomb, an operational bomb, who knew all the technology and who was selling this on the black market basically to anybody who could pay his price. And we know that he had sold this technology to Libya and to other countries," Mr Straw said.

There had to be "a new agenda in the face of this new information and threat", Mr Straw stressed. "The crucial thing is that the network is broken up, and in that respect we are getting full cooperation from the government of Pakistan," he said.

Mr Straw refused to be drawn on Mr Khan's pardon. "How Dr Khan is dealt with is an internal matter for the government of Pakistan and the only relative reassurance I provide is that there are relatively few people with the skills and experience and access to nuclear material and equipment that Dr Khan had for many years," he said.

The fact that Mr Khan's network had been smashed was "a huge tribute to American and to British intelligence", Mr Straw said. "The whole of the world, literally, owes them a very great debt of gratitude for what they have done and I venture to suggest... that the only thing they didn't quite get right, by a margin, was the scale of the activity which they had begun to uncover." -AFP