Space radiation triggered a glitch in the on-board computer system causing the recent crash of Russia's Mars probe, Federal Space Agency head Vladimir Popovkin said on Tuesday.

"Two components of the onboard computer system were spontaneously rebooted and it switched into a standby mode," he said.

"The most likely reason [for the glitch] is the impact of heavy charged space particles," he said.

Another possible cause could have been defective microchips imported from abroad, he said.

"The use of imported microchips is not only our problem," he said, adding that NASA and the U.S. Defense Department were also concerned by illegal imports of those products.

A government commission has ruled out any "external or foreign influence" on the spacecraft, including alleged electromagnetic emission from a U.S. radar in the Pacific Ocean.

Phobos-Grunt, Russia's most ambitious planetary mission in decades, was launched on November 9 but it was lost due to a propulsion failure and fell back to Earth on January 15.

Popovkin previously suggested that certain forces in the Western Hemisphere, which is a shadow zone for Russia, might be shooting down Russian spacecraft.

According to NASA, Russia has failed in all 17 of its attempts to study the Red Planet close-up since 1960. The most recent failure before November 2011 occurred in 1996, when Russia lost its Mars-96 orbiter during launch.