In a burgeoning criminal investigation, former prime minister Ehud Olmert's bureau chief was summoned to an official Justice Ministry hearing Monday on suspicion of illegally wiretapping Olmert's telephone conversations during his tenure as industry, trade and labor minister. Shula Zaken is suspected of listening in on Olmert's phone conversations during his three-year tenure as minister on a near-daily basis, as well as ordering other secretaries in the ministry to do so on her behalf, the Justice Ministry said. "On the occasions when the ministry's secretaries were told to eavesdrop on [Olmert's] conversations, Zaken ordered them to report on their content, and in some cases, she had them transcribe the conversations," the State Prosecutor's Office said in a statement released Monday. Olmert has told police that he was unaware his phone calls were being intercepted, the Justice Ministry statement said. Zaken has already been questioned by police on the issue. Both Zaken and Olmert have repeatedly denied any criminal wrongdoing. After the hearing, the State Prosecutor will decide whether to press charges against her. Zaken already faces fraud charges for allegedly engaging in bribery to influence promotions within the Tax Authority.