Pakistan has released a senior scientist who was detained in November 2003 on charges of helping his chief Abdul Qadeer Khan in proliferating nuclear equipment and know how to Libya, North Korea and Iran, news reports said Saturday.

Farooq Ahmed returned home Thursday after 30 months of "debriefing", his son Asim Farooq told the Daily Times newspaper in Islamabad.

Ahmed, who worked as director general procurement at the country's premier nuclear facility Kahuta Research Laboratories, was arrested Nov 23, 2003 along with two of his colleagues.

Their arrests followed startling revelations in October 2003 by the UN nuclear watchdog, the International Atomic Energy Agency, that Pakistani scientists were involved in nuclear black-marketing.

Ahmed's residence was heavily guarded and he was not allowed to meet anyone.

Reports also said that Ahmed and other KRL officials released earlier have given an undertaken not to leak any information about the debriefing sessions they attended at undisclosed locations.

Venerated as a national hero, A.Q. Khan publicly confessed to his involvement in the scandal in February 2004 but was pardoned by President General Pervez Musharraf for putting Pakistan on the nuclear map.