The blast was detected on the flight data recorder of the then-Polish President Lech Kaczynski's plane, which crashed in 2010 near the Russian city of Smolensk, Polish Defense Minister Antoni Macierewicz told local media reporters on Saturday.

"Back then we established that an explosion took place, eventually destroying the plane. Now we know significantly more… We discovered the moment of the explosion in the records of one of the flight recorders, it was identified," Macierewicz said on Saturday.

In April 2017, the second Polish commission tasked with investigating the crash released new materials, saying that a blast hit the jet before it hit the ground. The Interstate Aviation Committee (IAC) rejected the conclusions made by the Polish commission as the technical committee has not revealed any traces of the explosives’ impact on the plane.

Kaczynski’s plane crashed attempting to land at an airfield covered in heavy fog near Smolensk. None of the 96 passengers, including eight crew members and a number of high-ranking Polish officials, survived. In 2011, the IAC released a final report on the results of the technical investigation into the accident, in which the crew’s decision not to route the plane to an alternative airfield was named as the direct cause of the crash. The report also outlined serious deficiencies in the way the aircraft’s crew was trained and how readiness for the flight was assessed.

The first Polish commission under the leadership of then-Interior Minister Jerzy Miller came to similar conclusions, saying the catastrophe was due to flying below the permissible height as the presidential plane started landing despite thick fog. The current Polish authorities did not agree with the IAC report and the conclusions of the Miller commission, and decided to establish a second commission.