WARSAW, June 21 (Xinhua) -- Around 1,300 documents from the Russian investigation into the April 10 air crash in Smolensk were transferred to the Polish General Prosecutor's Office on Monday by Russian diplomatic post, local media reported.

The files include witnesses' testimonies, protocols, and photographic documentation from the on-site investigation as well as protocols from autopsies, according to spokesman for the General Prosecutor's Office Mateusz Martyniuk.

"The files will immediately be transferred to the Military Prosecutor's Office responsible for the investigation," he said, adding that files were in Russia so the military prosecutor's office will have to appoint sworn translators who will translate them into Polish.

The April 10 air crash near Smolensk claimed the lives of 96 Polish VIPs including President Lech Kaczynski and his wife Maria.

Investigation into the crash is carried out by the Military Prosecutor's Office in Warsaw.