Jaroslaw Kaczynski, who lost in the recent early presidential elections, said the current administration was "completely abandoning" the investigation into the crash that killed his twin brother, President Lech Kaczynski and 95 others.
Speaking in Warsaw, Kaczynski told an audience that President Bronislaw Komorowski and his top ministers "must disappear from the Polish political arena once and for all."
Russia's RIA Novosti said Kaczynski also hinted that a "foreign state" played some part in the crash, which occurred in April as the presidential plane tried to land in Russia in poor weather.
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