"A factor in the development of a special situation in the flight could be the wrong data about flight speed on pilot’s indicators which was likely due to iced pitot tubes (speed probes) while their heating systems were shut off," said the Russian Interstate Aviation Committee (IAC) which investigates aircraft incidents.
The Antonov An-148 plane took off from Moscow's Domodedovo airport on Sunday and went down in a field around 70 kilometres southeast of Moscow shortly after. Sixty-five passengers and six crew members on board all died.
The IAC said it has completed analysis of the on-board recorder and would still need to analyse the black box which recorded conversations in the cockpit. It would also look at whether the speed probes could have malfunctioned.
Iced-over pitot tube instruments were previously named as the likely reason behind the crash of the Air France 447 flight into the Atlantic in 2009, killing 228 people on board.
Emergency workers have been combing through the deep snow at the site of Sundays accident.
Today, the emergency ministry said they recovered 1400 body parts and 500 plane fragments.
Authorities were taking DNA samples from relatives of the victims in order to complete identification.