Iranian engineers outwitted their American counterparts over the global positioning system (GPS) technology employed on Tehran's recently captured unmanned spy drone.

This according to Christian Science Monitor (CSM), which reported that by piecing apart previously downed spy aircraft by the United States, Iranian specialists were able to identify holes on the drone's navigational behaviour.

That security flaw, the CSM report said, led to the take over of the RQ-170 Sentinel when it went on a mission near the border that Iran shares with Afghanistan in early December, which eventually allowed Iranian experts to land the vehicle safely and relatively intact.

American officials have confirmed that it lost a spy drone and even asked Tehran to return the aircraft, which Iranian authorities rebuffed.

According to CSM, Iranian engineers claimed that studies conducted on crashed UAVs earlier this year provided clues that the GPS mechanism that guides American spy drones could easily be exploited.

As a result, an 'electronic snare' was created and laid out by Iranian specialists, which CSM said functions "by putting noise jamming on the communication," used by the remotely-piloted aircraft.

Through that technique, an unidentified Iranian interviewed by CSM revealed: "You force the bird into autopilot. This is where the bird loses its brain."

The same engineer described the whole process of guiding the RQ-170 to its 'new home' in Iran as a simple task of hacking an email account.

According to Y! Tech, vulnerabilities on GPS used by spy drones have been known issues that U.S. authorities were aware of and the problem reportedly dates back in the late 1990s.

It appears that the glitch have not been resolved, experts noted, which resulted to the embarrassing capture of the Sentinel spy plane that even prompted U.S. President Barack Obama to formally send request for the Islamic Republic to return the drone.

As expected, Tehran declared that not a piece of the vehicle will be sent back to Washington, insisting that the aircraft was utilised to violate its airspace and conduct spy mission.