The question of whether the crew were pressured to land remains unanswered, an official said. One of those in the cockpit has been identified.

The plane crashed as it tried to land at Smolensk in western Russia on 10 April, killing dozens of senior Poles.

The investigation, which was releasing its preliminary findings of the investigation, confirmed crew were repeatedly warned about poor weather.

Alexei Morozov, head of the technical commission examining the crash, said air traffic controllers had warned twice that visibility was 400m (1,312ft) and that "there were no conditions for landing".