The Shabak Israel Security Agency summoned leftist activist Yonatan Shapira for a preliminary inquiry on Sunday, according to the Haaretz news service. Shapira spray-painted "Free Palestine" on remnants of the walls of the Warsaw ghetto on June 27, prompting Holocaust survivors to ask Polish authorities to investigate him.
The 38-year-old Shapira is a former military helicopter pilot. He initiated a letter by 27 pilots in September 2003 in which they said they refused to take part in "the killing of civilians".