Twelve bodies were brought out Friday by rescuers from the crash site where a Sukhoi Superjet 100 airliner went down in Indonesia Wednesday, officials said.
The bodies have been taken to the main search coordination site at Pasir Mangis in western Java.
The information was confirmed by the Russian commission helping investigate the incident.
"The Russian commission is working closely with the Indonesian headquarters to find out the circumstances of the crash and in the rescue effort. According to the Indonesians, they have found 12 bodies," said Dmitry Solodov, the press attaché of the Russian embassy in Jakarta.
The aircraft, carrying at least 45 people on board, hit steep ground at an altitude of 5,200 feet near Jakarta during a demonstration flight. Eight of those on board were Russian, including the flight crew.
Indonesian rescue teams finally reached the crash site Friday by roping down from helicopters. Further search teams were heading to the scene, hoping to clear landing sites for helicopters in order to bring out the bodies and wreckage.
Meanwhile, simulator trials held at a flight research centre near Moscow suggest pilot error was a likely factor in the accident, the Izvestia daily reported Friday.
The trials simulated "various emergency situations and concluded that none of those could have been behind the crash", the paper said.
The SSJ-100's cockpit Terrain Awareness and Warning System (TAWS) informs pilots of approaching obstacles, a source at the centre said.
"You just cannot miss the alert signal - if there is a danger, the system puts an alert message onto the central display, and a red light indicator as well as a speech alert come on. Besides, automatic systems can intervene to try to help the plane avoid a collision," the source said.
The pilots may have turned off the alert system in order to speak with the passengers or show them around the cabin, he said.
Another expert said the pilots may have "stopped taking notice" of the alert system as it is "nearly always on" in mountainous regions.
One flight safety expert dismissed the test results for giving an incomplete picture.
"Tests in a simulator don't tell the whole story. Tests with a real aircraft are possible only after the discovery and decoding of the aircraft's flight data recorders," said an unnamed expert from the State Scientific Research Centre for Civil Aviation.
"Decoding of the recorders is vital, to recreate the flight parameters at the time of the crash," he said.
Another expert said there were possibilities about the apparent failure of the Terrain Awareness and Warning System.
"There are three possibilities - the first is that it was not working, the second that it was turned off or they didn't pay attention to it, or that it gave an erroneous indication," he said.