Sensitive military technology used in nuclear weapons and missiles can be bought easily in the United States and illegally exported abroad, a government audit has found.

An undercover investigation by the Government Accountability Office (GAO) revealed that parts employed in atomic bombs, guided missiles, warplanes and improvised explosives could be purchased without difficulty and then exported to countries considered key transit points for terror networks.

"Using a bogus front company and fictitious identities, GAO purchased sensitive items including night-vision scopes currently used by US soldiers in Iraq and Afghanistan to identify targets, triggered spark gaps used to detonate nuclear weapons, electronic sensors used in improvised explosive devices, and gyro chips used in guided missiles and military aircraft," the agency wrote in a report issued Thursday.

"In the wrong hands, this technology poses a risk to US security, including the threat that it will be reverse engineered or used directly against US soldiers," it said.

More than 145 defendants have faced criminal charges for violations of export control laws, and about 43 percent of those cases the accused were trying to illegally transfer items to Iran or China, according to the Justice Department.

Officials at the State Department, Commerce Department and law enforcement agencies said they were not surprised by the GAO's findings and "admitted that there is no practical way to ensure seemingly unsuspicious packages can be consistently identified and searched," the report said.