Edmund Klich, who heads up the Polish air accident commission, says Russian air traffic controllers advised the pilots against landing the aircraft at Smolensk due to thick fog, the Russian news agency RIA Novosti reported Wednesday.
"The pilots ignored all danger warnings shown by the aircraft's automatic controls, and took an undue risk," Klich says.
The Soviet-made Tu-154 jet crashed April 10 killing all 96 people aboard including Polish President Lech Kaczynski, his wife, and top state officials.
The group was en route to a memorial ceremony for victims of the 1940 Katyn massacre in which Soviet secret police executed thousands of Polish military officers.
Investigation of the cause of the crash is continuing.