Polish military prosecutors on Wednesday questioned two Russian air traffic controllers from the airport where President Lech Kaczynski's plane crashed in April 2010, Polish Radio reported.
Pavel Plusin and Viktor Ryzhenko were questioned in Moscow.
"The questioning lasted eight hours, which is allowed by Russian law. The prosecutors are satisfied with the outcome," Prosecutor General Andrzej Seremet was quoted as saying.
He added that the witnesses will be asked additional questions soon, but revealed no details.
Polish prosecutors in Moscow are going to look through the Russian files on the Smolensk air disaster and interview more witnesses as they believe that the pilots were not given vital information on weather and other conditions as they approached Smolensk on 10 April, the radio station said.
The Polish Interior Ministry said earlier on Wednesday it would delay the release of a report on the causes of the plane crash until late March.
Lech Kaczynski, his wife and dozens of high-ranking Polish officials were killed when their Tu-154 plane crashed on April 10 near the Russian city of Smolensk while landing in thick fog.
The Moscow-based CIS International Aviation Committee (MAK) released a report on January 12 citing pilot error as the main cause of the tragedy. Polish experts and officials have criticized the report, saying it lacks evidence.
Jaroslaw Kaczynski, a Polish opposition leader and the late president's twin brother, has blamed Russia for the tragedy.
WARSAW, February 9 (RIA Novosti)
