Former Vice Defense Minister Shin Beom-chul has left the ruling People Power Party (PPP) after running unsuccessfully in last month's general elections, the second time his bid for the National Assembly has failed. "I'm going to quit politics," Shin told Yonhap News Agency on Thursday when asked why he left the ruling party. "I have lost in the same constituency for the second time and I think I should leave it to people behind me." Shin's departure came at a time when an investigation is picking up speed into suspicions that undue influence was exerted over a military probe into last year's death of a young Marine killed in an operation to save downpour victims. Shin, who was serving as vice defense minister at the time, is expected to be summoned for questioning. Some observers said his departure from the PPP could be aimed at lessening the burden that his questioning could bring on the party. Source: Yonhap News Agency