Washington: Four key US lawmakers have asked the Bush administration to seek direct access to disgraced Pakistani scientist A Q Khan to best deal with the ramifications of his infamous nuclear black market.

"It is in the interest of the United States, Pakistan, and indeed the rest of the world, that the full actions of A Q Khan become known so that we can best deal with the ramifications," the four said in a letter to Secretary of State Condoleezza Rice on Thursday.

"We strongly urge you to work with the new civilian leadership in Pakistan to not only grant the United States direct access, but to ensure that Dr Khan is not released from house arrest," they said.

The signatories were Howard L Berman and Ileana Ros-Lehtinen, Democratic chairman and ranking Republican member of the House foreign affairs committee and Gary L Ackerman and Mike Pence, Democratic chair and ranking Republican member of the subcommittee on the Middle East and South Asia.

Ever since his network was publicly revealed in 2003, US Congress has been very concerned about the lack of access that the Government of Pakistan has given the US States to interview A Q Khan about the extent of his activities, they said.

"A full investigation on the actions and activities of Dr Khan has therefore not been possible," they noted expressing "deep concern about new information that has surfaced regarding the nuclear proliferation activities of the A Q Khan network."

Recent reports indicate that the Khan network may have transferred designs for smaller, more sophisticated nuclear warheads than were previously known publicly.

These designs could allow states like Iran to more easily produce smaller nuclear warheads for its ballistic missiles, significantly increasing the potential nuclear threat from Iran to Israel and our European allies, the lawmakers feared.

"An Iran with nuclear weapons capability is one of the gravest national security threats facing the United States and our friends and allies," they said. "Now, more than ever, we must be allowed to gain direct access to A Q Khan to conduct a full investigation and find out what designs were smuggled and to whom."

"The United States no longer has the luxury of relying on second-hand information from Pakistani authorities on Khan's activities where our fundamental national security is concerned," the lawmakers said.

A study by former top UN arms inspector David Albright for the Institute for Science and International Security has suggested that an international smuggling ring once run by A Q Khan may have given Iran - and other "rogue" nations - blueprints for a miniature nuclear warhead first developed for his country's weapons programme.

The now-defunct ring, previously known to have sold bomb-related parts to Libya, Iran and North Korea, also acquired designs for building a more sophisticated compact nuclear device that could be fitted on a type of ballistic missile used by Iran and other developing countries, the study suggested. The US has said it is against freeing A Q Khan even as it thinks that the nuclear black market run by his network is now out of business.

Source : IANS