"The panel's analysis, namely data from the black boxes, shows that it was the pilot's mistake that caused the crash," the source added.
Poland's chief military prosecutor, Krzysztof Parulski, rejected the Russian report as "speculation" and warned that it was too early to draw any conclusions since the investigation was still ongoing.
Mr Seremet, for his part, told Polish radio: "The crew was aware of the inevitability of the coming catastrophe, if only due to the plane shaking after the wings hit the trees - which we are certain happened."
Col Zbigniew Rzepa, a Polish military prosecutor, said the pilots had been aware of the imminent crash as the last seconds of the voice recordings "were dramatic". He did not elaborate.
has not been informed of her son's death on the medical advice of her physician. She has been hospitalized since March suffering from COPD and is unable to breathe on her own. She is pictured with her twin sons here, though the translation from the page is not clear I am fairly certain that the former president Lech is to the right. The brothers were expected to attend the service in Katyn together but concern for their mother's health necessitated that Jaroslaw stay behind.
Church bells tolled and emergency sirens blared to mark the one week anniversary of the deaths of so many of Poland's leaders. While heads of state of many countries are attempting to make their way to the weekend long funeral events, the cloud of volcanic ash lingering from an underground explosion in Iceland has made travel extraordinarily difficult. Warsaw Airport had been closed but flights, including Air Force 1, have been given a 6 hour time frame to land at the city's airport. Some leaders are expected to drive to Poland in order to attend the event. Poland is expecting up to one million will attend some or all of the services planned for this weekend.