Top Polish officials in the cockpit of the plane of president Lech Kaczynski that crashed in Russia put pressure on the crew to land in dangerous weather conditions, investigators said on Wednesday.
Kaczynski died with 95 others when his presidential jet crashed on April 10, 2010, as it attempted to land in fog near the city of Smolensk in northwestern Russia in Poland's worst postwar tragedy.
In a damning report listing Polish shortcomings leading to the crash that risks sparking tensions with Warsaw, the Russian probe hinted that the plane was ordered to land as Kaczynski would have been unhappy if it was diverted.
Tatyana Anodina, head of the Moscow-based aviation commission investigating the tragedy, confirmed that top Polish officials had been in the cockpit of the Tu-154 plane but also revealed they had pressured the crew.
"The presence in the cockpit of high-ranking officials -- Poland's air force chief and head of protocol -- and the expected negative reaction from the main passenger put psychological pressure on crew members and affected decision making regarding the continuation of landing under any conditions," she said.
She did not identify the "main passenger" but it appears she was referring to Kaczynski. She said it was the captain of the plane who was expecting the negative reaction.
"Psycho-emotional tension" and a "conflict of motives" were among key factors contributing to the crash, said Anodina.
"And let me stress -- under conditions unsafe for landing, under conditions of unjustified risk."
"There was a strong motivation to perform the landing precisely at the airport of destination," she added.
In course of the flight, the crew "repeatedly received information about the absence of adequate weather conditions" from the Severny airport in Smolensk and a crew of a Yak-40 plane plane that had landed there earlier, she said.
"Despite this, the Tu-154 crew did not make a decision to land at a substitute airport. This fact can be considered the start of a critical situation during the flight," she said.
Anodina said experts also found alcohol in the blood of the Polish air force chief Andrzej Blasik who was present in the cockpit of the plane.
Meanwhile, the pilots operating the plane had "substantial deficiencies" in their training, Anodina said.
The Russian-made Tupolev-154 was carrying Kaczynski as he prepared to attend a ceremony at Katyn forest commemorating the 70th anniversary of a World War II massacre of around 22,000 captured Polish officers by the Soviet secret police.
Poland and its Soviet-era master Russia have had uneasy relations since the demise of Communism and the collapse of the Soviet Union two decades ago. Yet Poles were struck by the level of public and official mourning in Russia following the tragedy.
But the crash and subsequent investigation have soon become highly politicised, with Poland sharply criticising Russia's handling of the probe.
After initially praising Moscow's cooperation, Polish Prime Minister Donald Tusk changed tack, calling the draft findings of the Russian investigation unacceptable and riddled with errors.
To further add to tensions, Kaczynski's twin brother and ex-prime minister Jaroslaw Kaczynski said he doubted that a body entombed in a Polish cathedral was that of his brother.
The final report was earlier handed "to the authorised representative of Poland via the Polish embassy in Russia" the aviation commission said.