WARSAW — Forensic testing has proven that two more victims of the 2010 plane crash in Russia that killed President Lech Kaczynski of Poland and 95 others were misidentified and buried in the wrong graves, Polish prosecutors said Wednesday.

The number of misidentified victims has now grown to six and highlights flaws in the handling of the crash’s aftermath in Russia. Such errors are deepening Polish distrust of its historic foe, while also fueling Polish conspiracy theories about the cause of the disaster.