The sarcophagus of president Lech Kaczyński and his wife Maria in the Wawel cathedral in Kraków will be the first to be opened on 14 November, according to sources close to the station.

The remains of the first couple will be transported to the department of forensic medicine of the Jagiellonian University.

At the end of November at least four other exhumations are set to be carried out, in Warsaw and Lublin. The RMF station said that all the 83 exhumations which have been planned are to be completed by the end of the year.

A total of 96 people died in the crash which happened in thick fog as the plane was attempting to land at the military airport in Smolensk.

In previous years, nine exhumations have been carried out. The prosecution later admitted in an official statement that six bodies had been wrongly identified and consequently buried in the wrong graves, Radio Poland reported.

The governing PiS party in Poland has long challenged an official report into the crash issued by the previous Polish government which cited a catalogue of errors on the Polish side, while also pointing to errors made by Russian staff at the control tower of Smolensk Military Airport.

A Russian MAK report placed all the blame on the Poles.