Tokyo's Metropolitan Police Department began investigating on Monday the virtual currency theft at a digital money exchange Coincheck Inc., which said last week 58 billion yen ($532 million) in the cryptocurrency NEM had been stolen by hackers.The police asked Coincheck officials about the incident before proceeding to a full-fledged investigation into transaction and access records, investigative sources said.The police may ask overseas investigating authorities for cooperation if they find traces of unauthorized access to the Tokyo-based exchange's system from outside the country, but "it…READ FULL ARTICLE