Non-crew members were present in the cockpit of a plane that crashed killing the Polish president and more than 90 others, an investigation has found.
One of the non-crew members has been identified, though he or she was not named by officials.
The plane crashed as it tried to land in western Russia on 10 April, killing President Lech Kaczynski and dozens of senior Poles.
The investigation confirmed crew were repeatedly warned about poor weather.
An air traffic control official "warned twice that visibility was 400m (1,312ft) and that were there were no conditions for landing", said Alexei Morozov, head of the technical commission examining the crash, releasing the preliminary findings of the investigation.