More than a million Chinese counterfeit electronic parts are estimated to be in use in US military aircraft, according to a US Senate report released Monday saying the discovery jeopardizes safety and national security.

The Senate Armed Services Committee said its year-long investigation launched by Democratic chairman Carl Levin and ranking Republican John McCain uncovered 1,800 cases of bogus parts, including on the US Air Force's largest cargo plane, special operations helicopters and Navy surveillance planes.

The 112-page report "outlines how this flood of counterfeit parts, overwhelmingly from China, threatens national security, the safety of our troops and American jobs," Levin said.

"It underscores China's failure to police the blatant market in counterfeit parts -- a failure China should rectify."

The report also said the Chinese government denied visas to committee staff to travel to the Asian giant as part of the committee's probe, with a Chinese embassy official saying the issue was sensitive and that a negative report could end up "damaging" US-China relations.

While the senators lay the blame squarely on China, the report said US authorities and contract companies contributed to the vulnerabilities to the defense supply chain by not detecting the fakes, or routinely failing to report suspected counterfeiting to the military.

"The failure of a single electronic part can leave a soldier, sailor, airman or Marine vulnerable at the worst possible time," the report said.

"Unfortunately, a flood of counterfeit electronic parts has made it a lot harder to prevent that from happening."

The fakes included parts in the Electromagnetic Interference Filters used in night missions and in operation of "hellfire" missiles on SH-60B Navy helicopters.

The were also found in memory chips in the display systems of C-17 Globemaster III and C-130J military cargo planes, and refurbished ice detection modules on the Navy P-8A Poseidon, modified Boeing 737 aircraft incorporated with anti-submarine and anti-surface warfare capabilities.

The report said the Defense Department "lacks knowledge of the scope and impact of counterfeit parts on critical defense systems," and that the use of unvetted independent distributors for the supply of critical military parts results in unacceptable risks to national security and safety.