"A factor in the development of a special situation in the flight could be the wrong data about flight speed on pilots' 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 (40 miles) 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.
Authorities were taking DNA samples from relatives of the victims in order to complete identification. The emergency ministry added that it would on Tuesday lifting the main plane debris out of the crater formed upon impact.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)