The Bush administration based a crucial prewar assertion about ties between Iraq and Al Qaeda on detailed statements made by a prisoner while in Egyptian custody who later said he had fabricated them to escape harsh treatment, according to current and former government officials.
  The officials said the captive, Ibn al-Shaykh al-Libi, provided his most specific and elaborate accounts about ties between Iraq and Al Qaeda only after he was secretly handed over to Egypt by the United States in January 2002, in a process known as rendition.
  The new disclosure provides the first public evidence that bad intelligence on Iraq may have resulted partly from the administration's heavy reliance on third countries to carry out interrogations of Qaeda members and others detained as part of American counterterrorism efforts. The Bush administration used Mr. Libi's accounts as the basis for its prewar claims, now discredited, that ties between Iraq and Al Qaeda included training in explosives and chemical weapons.