Vandals damaged and scrawled anti-Semitic graffiti on the family tomb of leading Polish writer, editor and former anti-Communist dissident Adam Michnik.

Polish Radio reported that the defacement of the tomb of Michnik’s father, a prominent Jewish communist, and his non-Jewish mother was discovered Monday evening by a member of the public who had been visiting Warsaw’s Stare Powazki cemetery. Part of the tomb was broken at the base and a Star of David hanging from a gallows was scratched on its surface.

Michnik, a prominent anti-Communist dissident in the 1960s and 1970s, was a key activist in the Solidarity movement and co-founder and editor-in-chief of the liberal Polish newspaper Gazeta Wyborcza.

“I would like to believe that this was done by a person with severe emotional or psychological problems, who had heard propaganda against Gazeta [Wyborcza] and the Michnik family,” Polish Radio quoted Michnik as saying. “Because this is so contrary to Polish tradition. The grave is a sacred place for us.”

Michnik, who identifies as a Pole of Jewish origin, said that this was the third and most serious act of vandalism on the tomb in six years.