What is reported to be the body of former exiled Polish leader Ryszard Kaczorowski has been exhumed in Warsaw.
He was onboard the Polish presidential plane when it crashed in Smollensk in Russia in 2010.
His church tomb is believed to have been opened, along with the grave of another victim, amid fears that their remains could have been switched by mistake.
"The bodies will be examined by using computer tomography," said prosecutor Marcin Maksjan.
"DNA examinations will be decisive."
The presidential plane came down in Russia while attempting to land in thick fog.
All 96 people onboard were killed - including Polish President Lech Kaczynski.
They had been on their way to a memorial for Polish officers, massacred by Soviet forces in 1940.
