ISTANBUL Authorities issued detention warrants on Oct. 30 for four Istanbul Municipality officials as part of an espionage investigation linked to a major data-leak case . Istanbul Mayor Ekrem İmamoğlu was arrested last week in connection with the same probe, alongside his former adviser Necati Özkan and journalist Merdan Yanardağ. The new charges against İmamoğlu stem from an investigation into alleged ties between his 2019 mayoral campaign and businessman Hüseyin Gün, who was arrested in July