A prominent United States lawmaker will head a hearing to examine whether the nuclear weapons technology network headed by disgraced Pak scientist A Q Khan has been dismantled as claimed by the Bush Administration or has merely started operating under a different guise.

The prime focus of the hearing is to review the findings of International Institute for Strategic Studies about the Khan cartel and see if the nuclear black market network has been truly dismantled or continues to be operated by his associates.

Coverage: Pakistan's nuclear bazaar

Congressman Gary Ackerman, the Democrat lawmaker from New York who maintains a sharp eye on the goings on with the Khan network, will be in charge of a hearing 'AQ Khan's Nuclear Wal-Mart: Out of Business or under New Management?'

"Khan created the world's most dangerous nuclear network responsible for the single worst case of nuclear proliferation in the last 50 years. Kahn's network sold nuclear weapons technology to North Korea, Libya, Iran and perhaps other nations," he said.

"Although US President (George W) Bush claimed that Khan's nuclear trading cartel was shut-down, a new report by the International Institute for Strategic Studies raises fresh questions regarding whether Kahn's network is truly out of business.

"The IISS report makes clear that the full scope of his operation remains unknown and emphasizes that the lack of accountability for this enormous crime could lead others to replicate Khan's efforts," Ackerman, chairman of House Foreign Affairs Subcommittee on the Middle East and South Asia, said in a statement.

Witnesses from the administration are not scheduled to appear before Ackerman's panel. Mark Fitzpatrick, senior fellow for non-proliferation at the International Institute for Strategic Studies; David Albright, president of the Institute for Science and International Studies and Lisa Curtis, senior research fellow at The Heritage Foundation's Asia Studies Center will be testifying.