A legislation has been introduced in the US House of Representatives aimed at cutting off military aid to Pakistan unless American officials are able to question disgraced nuclear scientist A Q Khan.

Alleging that Khan is a "loose nuke scientist with proven ability to sell the worst weapons to the worst people", Congressman Jane Harman said on Thursday on the House floor that his legislation in this regard provides a path for the Zardari government to do the right thing.

"To allow the US to evaluate the full extent of Khan's proliferation activities in order to halt any ongoing or future harm," Harman, Chair of the Homeland Security Subcommittee on Intelligence and Terrorism [Images] Risk Assessment, said.

The bi-partisan legislation conditions future military aid to Pakistan on two things: the Pakistani government make Khan available for questioning and it monitor his activities.

The House Resolution HR 1463 is co-sponsored by about half a dozen senior US lawmakers, including Ellen Tauscher, who is Chair of Armed Services Subcommittee on Strategic Forces, Ed Royce, Ranking Member of the Foreign Affairs Subcommittee on Terrorism, Non-proliferation and Trade and Gerry Connolly.

"Convicted in absentia by the Dutch government for nuclear espionage, beginning in the mid-1980s, Khan is widely believed to have provided nuclear weapons technology to Iran, North Korea, Libya and possibly Syria and Iraq," he said.

His network involved front companies and operatives in Dubai [Images], Malaysia, Singapore, South Africa [Images], South Korea, Switzerland [Images] and Turkey, he added.

Though much of the network was taken down following his confession, there is no conclusive evidence that it was destroyed, Herman said.

Considered a pariah abroad but a hero at home, Herman said the task to monitor Khan got a lot tougher when a Pak High Court ordered his released from house arrest last month.

"At the recent Wehrkunde Security Conference in Munich, Pakistani Foreign Minister Shah Mehmood Qureshi astonished delegates, telling us that his government had not decided whether to challenge the court decision but that Pakistan would continue to monitor Khan," he said.

"For those who stay awake at night worrying about Iran's increasing mastery of centrifuge technology and the ability of terror groups to access nuclear components, Pakistan's action is distressing," the lawmaker said.

"When Khan "confessed" in 2004 to his illegal nuclear dealings, he was promptly placed under "house arrest" and pardoned by then President Pervez Musharraf [Images]. The US government was denied access to him and was never able to question him about what he did and what else he knew," the lawmaker said.