Polish authorities on Monday began exhuming the remains of a late president, his wife, and other victims of a 2010 plane crash in Russia, rekindling a probe that has become a political flashpoint, to investigate whether the crash involved foul play.

Prosecutors have ordered the opening of the sarcophagus of Lech Kaczynski, who was Poland’s president at the time, to perform an autopsy. The Polish government said it was necessary to establish what brought down the aircraft.

Many senior figures in the conservative government that took office last year have consistently challenged official reports, by the previous Polish administration and a Moscow-based committee which blamed thick fog and a pilot error. The Polish report also put part of the blame on a decrepit Russian airport and misleading communications with Russian flight controllers on the ground.

Soon after coming to power in November, Defense Minister Antoni Macierewicz formed a committee of experts from various fields to look into the crash once again. Mr. Macierewicz has said he believes the airplane may have disintegrated midair and that traces of explosives had been found on the wreckage, which remains in Russia.

Investigating teams in Moscow and Warsaw have refuted those claims.

The bodies of 83 of the 96 victims of the crash are set for exhumation over the course of about a year. Prosecutors said they would be looking into errors that may have been made six years ago, which include possible mistakes in identification of victims.

The decision to exhume victims has caused great controversy. Some families vehemently oppose the plan while others want to put to rest suspicions that Russian investigators were careless in the chaotic aftermath of the crash.

“I’ll be getting a chance to find out whom I buried, and to bury my husband with dignity,” said Magdalena Merta, the widow of Tomasz Merta, a deputy minister of culture who was on the doomed flight.

Jaroslaw Kaczynski, the head of Poland’s ruling party, said recently he agreed with the prosecutor’s plan. Scores of officials from his Law and Justice party and his twin brother President Lech Kaczynski died in the Polish military aircraft.

Cockpit recordings showed no evidence of foul play, instead revealing nervousness among the crew about poor weather in Smolensk, a provincial town in western Russia. President Kaczynski was on route to a commemoration of more than 20,000 Polish prisoners of war shot by Soviet secret police in what is now known as the Katyn Massacre of 1940.

The remains of Lech Kaczynski and his wife are expected to be interred again at a crypt of Krakow cathedral later in November.