Prosecutors on Wednesday gave Poland more documents from their investigation into the plane crash that killed Polish President Lech Kaczynski and 95 others.
Saak Karapetyan, head of international relations for the Prosecutor General's Office, handed over 14 volumes to Polish diplomat Longina Putka just days before the first anniversary of the crash.
Russia previously has provided Poland with an array of documents about the crash in Smolensk last April 10. Karapetyan says the new documents included questioning of Russian air traffic controllers who communicated with Kaczynski's plane.
Polish authorities say the pilots' decision to attempt landing in heavy fog was a key reason for the crash, but they believe that Russian air traffic controllers and the airport's lack of sophisticated navigation equipment also played a role.