A top Pakistani general says the CIA's use of a fake polio vaccination program during the hunt for slain Al Qaeda chief Osama bin Laden represented a “breach of trust” between the US and Pakistan's government. Bin Laden was killed when US special forces in a secret raid in May. It has since been reported the CIA used a fake international polio eradication program as a front to track the fugitive terrorist leader down in the city of Abbottabad. General Nadeem Ahmed, a member of the Pakistani board of inquiry into the US raid, said in an interview with 774 ABC Melbourne's Jon Faine that the CIA's undermining of people's trust was “unfortunate”. General Ahmed, the former head of the Pakistan National Disaster Management Authority, said the inquiry into the raid had begun, but was reluctant to divulge details.