The escape of an alleged rapist from a Kawasaki prosecutor's office interrogation room this week has highlighted the insufficient security steps at such branches as well as the apparent lax guarding of suspected criminals.

Police Friday restarted interrogating Yuta Sugimoto, 20, while also looking into possible involvement by his former classmates, who may have helped him escape.

Prior to his escape from the Kawasaki branch of the Yokohama prosecutor's office, Sugimoto denied involvement in the alleged group rape and violent robbery of a woman in Asao Ward, Kawasaki, on Jan. 2.