Police have arrested a Tokyo man for putting up a poster without permission inside a bookstore where copies of “The Diary of a Young Girl” by Anne Frank has earlier been vandalized, investigative sources said Thursday.

The police are looking into whether the man, who was described as being in his 30s, is connected with a wave of vandalism that saw more than 300 copies of the diary and other books related to Anne Frank damaged at public libraries in Tokyo, the sources said.

The unemployed man has hinted at his involvement in the incidents, but his statements have so far been ambiguous and require further investigation, the sources said.

Footage from security cameras reportedly show the man wandering back and forth inside the bookstore in the Ikebukuro district in February.

The police arrested him March 7 after finding he had put up the poster inside the bookstore without permission a day after the vandalism was discovered there, the sources said.

The content of the poster was not made known.

The damage to the books in public libraries and the bookstore has been reported since late February.

Frank, a Jewish girl who lived in Amsterdam, wrote the diary while hiding from the Nazis during the Holocaust. It was added to UNESCO’s Memory of the World Register in 2009.