WARSAW, Poland (AP) — Poland's government says it is taking Russia to the United Nations' principal court over the continuing probe into the 2010 death of Poland's president in a plane crash in Russia and Moscow's refusal to turn over the wreckage.

The twin brother of late President Lech Kaczynski leads Poland's ruling party. Jaroslaw Kaczynski blames the crash on Moscow. He has made finding those responsible and recovering the plane's pieces for Poland's own investigation part of his political agenda.

Russian prosecutors say they still need the wreckage for their ongoing probe.

Aviation experts said the crash was an accident.

Foreign Minister Witold Waszczykowski said Wednesday that Poland is drafting up a complaint to the International Court of Justice in the Hague, Netherlands.

The court rules on disputes between nations and gives advisory opinions on legal questions.