Pakistani authorities have detained a senior aide of top Pakistani nuclear scientist Abdul Qadeer Khan amid a probe into the alleged leaking of nuclear information to Iran, his family said yesterday. "Major Islam ul-Haq was picked up by the security officials from the residence of Doctor Qadeer Khan at about 8:30pm on Saturday," his wife Nilofer said. Major Islam, a retired member of the military, is the principal staff officer of Qadeer Khan, who created Pakistan's nuclear bomb. "Some army officers, including members of the military intelligence, came in two jeeps and said they want to take Major Islam for interrogation," Nilofer said. Qadeer Khan headed the country's uranium enrichment facility, the Kahuta Research Laboratory (KRL), near Islamabad until retiring in 2002. Two KRL directors, Yasin Chohan and Farooq Mohammad, were taken from their homes in December for questioning. Chohan has since returned home but Farooq is still being questioned. Qadeer Khan had also been questioned earlier but officials denied his movements were restricted. Foreign office spokesman Masood Khan said last month "a very small number" of scientists were being questioned over allegations of leaking nuclear information to Iran and a subsequent request from the International Atomic Energy Agency (IAEA) to Pakistan for co-operation. The spokesman said Pakistan had placed some senior nuclear scientists under investigation because of information they may have co-operated with Iran's nuclear programme for "personal ambition or greed." No official comment was immediately available. **PHOTO CAPTION*** Pakistani nuclear scientist Abdul Qadeer Khan. (AFP/File/Tanveer Mughal)