WASHINGTON, June 16: The White House has said it is concerned that the Khan network may have distributed designs of nuclear warheads and uranium enrichment technology among the so-called rogue nations.

“We are very concerned about the A.Q. Khan network, both in terms of what they were doing by purveying enrichment technology and also the possibility that there would be weapons-related technology associated with it,” said National Security Adviser Stephen Hadley.

He was commenting on US media reports that members of a network of nuclear proliferators, allegedly headed by Dr A.Q. Khan, had on their computers a design for an advanced nuclear weapon.

Mr Hadley said it was this concern that caused the US to roll up the network “fairly successfully” four years ago.

“And part of that rolling up was to roll up the network and part of it was to pursue what kind of relationship the A.Q. Khan network had to individual countries with which they are dealing.”

Asked if he had seen evidence to suggest that the Khan network had passed on weapons technology to countries like Iran, Libya and North Korea, Mr Hadley said this was also a concern.

“We’ve had some concerns about it. If you go back and look at the stories written at the time that Libya decided to give up its nuclear and chemical programmes, there was some discussion at that time about what the A.Q. Khan might have passed in terms of weapons-related technology,” he said. “We’re obviously -- would be concerned about that technology being passed to any of A.Q. Khan’s customers in that period.”

Media reports about Dr Khan’s alleged involvement in providing weapon technology to Iran, Libya and North Korea followed a study by a former UN weapons’ inspector, David Albright, that the Khan network had plans for an advanced weapons system that might fit onto the sort of missiles possessed by North Korea and Iran.—Correspondent