On 10 April 2010, a Tupolev Tu-154 government aircraft of the Polish Air Force crashed during a landing approach to the Russian military airfield Smolensk-Nord. All 96 passengers, including Poland’s then President Lech Kaczyński, members of parliament, members of government, high-ranking officers, church representatives and senior government officials, were killed in the crash. The occasion for the flight was a joint Polish-Russian commemoration of the 70th anniversary of the Katyn massacre .
An investigation report by the Russian Intergovernmental Aviation Committee (MAK) blamed the crash on mistakes made by the Polish crew. In July 2011, the Polish investigative commission presented its own final report. The Polish investigators also spoke of pilot errors, but also addressed errors by Russian air traffic controllers and the sometimes poor technical condition of the airport.
Many supporters of Lech Kaczyńskis The Right and Justice Party (PiS), including Kaczyńskis The twin brother Jarosław, who has led the party since 2003, still doubt the results of the two investigation commissions. They suspect that the accident was an attack on the Polish president. When in 2015 the coalition of the Civic Platform and the Polish People’s Party was voted out of office and the PiS won an absolute majority in parliament, the investigations were resumed. The work of the new Polish investigative commission has not yet been completed. In April 2017, however, it presented a 40-minute video  that identified a deliberate explosion as the most likely cause of the crash.
This theory is now gaining plausibility due to current British investigation results. As reported by the Foreign Service of Radio Poland , investigators from the Forensic Explosives Laboratory (FEL) have found traces of explosives manufacturing materials, including TNT, on samples of aircraft debris. The 200 samples were sent by the Polish National Prosecutor’s Office to the laboratory under the British Ministry of Defence in May 2017, writes Radio Poland with reference to research by the conservative online portal wPolityce.pl and the weekly magazine “Sieci” . As early as February 2018, a British investigator involved in the investigation of the Lockerbie  attack had supported the thesis in a television interview .