Igor Yesipovsky, governor of the Irkutsk Region, was one of four people who died in the crash.
Investigators have ruled out engine failure as a cause of the accident. According to initial investigations, the helicopter struck a 25-meter (82-foot) tree.
The committee, which operates in post Soviet countries, said it has "finished work on piecing together the fragments of the helicopter and its engine."
"Preliminary analysis has shown that before the helicopter struck the obstacle, there were no failures in the helicopter's systems or engine."
The U.S. produced Bell-427 helicopter was discovered in the afternoon on May 11 around 60 kilometers southeast of the East Siberian city of Irkutsk.
The helicopter was on a routine observation flight, with Yesipovsky, as well as the region's first deputy prime minister Mikhail Shtonda, pilot Viktor Kunov and bodyguard Alexander Shostak on board.
The helicopter's black box is being analyzed, but is severely burned.
