The magistrate who is investigating the Siemens corruption case paid an unexpected visit to the company’s headquarters in Athens yesterday and came away with about 150 files that may shed further light on the case. The probe into whether the Greek branch of the German electronics and engineering giant had been making under-the-table payments to Greek politicians is in its 27th month without any charges having being issued. Sources said that magistrate Nikos Zagorianos collected papers from the company that were connected to information he had received from the American law firm Debevoise & Plimpton, which was also involved in the German part of the investigation. A day earlier, Zagorianos had questioned two Greek Siemens employees. It is believed that he will wrap up the questioning of witnesses in the first week of March and will issue charges by Easter.