Pakistan
From 1991—93, during the Prime minister Benazir Bhutto's government, an operative directorate of the ISI's Joint Intelligence Miscellaneous (JIM), conducted highly successful operations in Soviet Union. This directorate successfully procured nuclear material while many operative were posted as the Defence attaché in the Embassy of Pakistan in Moscow; and concurrently obtaining other materials from Romania, Albania, Poland and the former Czechoslovakia.
In January 2004, Dr. Abdul Qadeer Khan confessed to selling restricted technology to Libya, Iran, and North Korea. According to his testimony and reports from intelligence agencies, he sold designs for gas centrifuges (used for uranium enrichment), and sold centrifuges themselves to these three countries. Khan had previously been indicated as having taken gas centrifuge designs from a uranium enrichment company in the Netherlands (URENCO) which he used to jump-start Pakistan's own nuclear weapons program. On February 5, 2004, the president of Pakistan, General Pervez Musharraf, announced that he had pardoned Khan. Pakistan's government claims they had no part in the espionage, but refuses to turn Khan over for questioning by the International Atomic Energy Agency.
Read more about this topic: Nuclear Espionage