WASHINGTON: The United States warned Tuesday that reputed Pakistani scientist Abdul Qadeer Khan, who has regained freedom of movement in Pakistan, still risks spreading his nuclear weapons know-how.

It stopped short of criticizing its ally in the war on terror but recalled that Washington has long raised with Islamabad its fears about Khan, who five years ago admitted leaking nuclear secrets to Iran, North Korea and Libya.

‘Our concerns over the potential for... proliferation activities by Mr. Khan are well known to the Pakistani government. We believe that he remains a proliferation risk,’ State Department spokesman Ian Kelly told reporters.

A State Department official told AFP earlier on condition of anonymity that Khan represented a ‘serious’ risk.

‘We’re following this closely,’ Kelly added when asked about the development at the daily news briefing.

In February, a Pakistani court declared Khan a free man, five years after the reputed father of Pakistan’s nuclear bomb was effectively put under house arrest for operating a clandestine proliferation network.

Last Friday, the 72-year-old Khan complained to a high court that his movements were still being restricted by the government’s security arrangements on his behalf.

The court ordered the government to respond to Khan’s claim on September 4.

Local media quoted Khan as saying the restrictions had been withdrawn ahead of Friday’s hearing.

Khan told AFP the reports were correct but added he could not elaborate because the court had barred him from giving interviews to foreign media.

David Albright, a former UN weapons inspector and nuclear specialist, told AFP that ‘it is a mistake’ to remove restrictions on a man who cannot be ‘trusted.’He said there is a risk that Khan, who retracted his 2004 confession, will now be able to offer nuclear know-how to scientists from Iran, North Korea and any other rogue countries feared to be pursuing a nuclear weapons program.

Albright, president of the Institute for Science and International Security (ISIS), said Khan may now not just be motivated by money, but also a ‘bitterness’ with the West over his house arrest.

Last year, Albright wrote on the ISIS website that there were strong suspicions Khan could have sold Iran and North Korea blueprints for an advanced nuclear warhead.

He said the United States and the UN atomic watchdog, the International Atomic Energy Agency (IAEA), must be allowed to question Khan to learn if he had sold such plans to Pyongyang or Tehran.

But he told AFP Tuesday that the United States never used its leverage to arrange for such questioning amid fears it would provoke a ‘backlash’ in Pakistan, a key US ally.

American lawmakers in March introduced legislation aimed at cutting off military aid to Pakistan unless US officials could question Khan.

Albright said the US government should now push for Khan to be extradited to European countries or the United States for prosecution over possible violation of proliferation laws.

A second State Department official told reporters later Tuesday on the condition of anonymity that he expected US concerns to be raised again with the authorities in Islamabad, but could not confirm they had been.

US Secretary of State Hillary Clinton had expressed concerns when Islamabad High Court eased restrictions on Khan in February. — AFP