WARSAW, Poland—Polish military prosecutors say autopsies have confirmed that the bodies of two people killed in a 2010 plane crash in Russia that also killed the Polish president were switched, and they were buried in the wrong graves.

The prosecutors said Tuesday that the mistake was confirmed by autopsies done last week on Anna Walentynowicz, a legendary figure of Poland's Solidarity movement, and a female victim who has not been identified.

They were among 96 people, including President Lech Kaczynski, who were killed when their plane crashed near Smolensk, Russia, in April 2010.

In the aftermath of the crash Russian experts who identified the victims made several mistakes in their autopsy reports, sparking Polish anger. In some cases, however, Polish authorities and the victims' relatives were present during identifications.