Academic fled Cambodia for Australia. He now admits he was on Hun Sen's payroll / Hun Sen Adviser Wanted in Thailand Over Lim Kimya Killing / Japan-based Cambodian activist demands Hun Sen and PM son release his brother / Cambodia ex-PM Hun Sen set to return to diplomatic stage / Cambodia: Ex-dictator Hun Sen returns as chief of Senate / Cambodia's ex-leader Hun Sen unanimously voted in as senate president / Hun Sen becomes Cambodia's Senate president, allowing him to act as head of state when king is overseas / Cambodia's ruling party wins Senate election, paving the way for Hun Sen to act as its president