Russian investigators opened a criminal probe on Thursday into possible misconduct during preparations for the exhibition flight of a new Superjet 100 jet which came down in Indonesia.
The Investigative Committee said it would probe "the procedure for preparing the flight crew and also the technical condition of the craft itself before its departure from Russia."
The twin-engine plane vanished from the radar screens on Wednesday about 50 minutes into its exhibition flight. Rescuers at the scene said on Thursday they had found bodies but no survivors.
Initial reports on the number of people on board varied between 46 and 50. Russia's Investigative Committee said it believed the plane was carrying 48 crew and passengers of five different nationalities including eight Russians.
The Russian investigators said they would question the technical personnel who prepared the crew for the flight "and representatives of the Sukhoi Civil Aircraft company involved in making the plane and preparing it for operations."
The Russian committee said it was also studying the option of sending a team to Indonesia "that could be present for the investigation being conducted by the Indonesian law enforcement authorities."