South Korea\'s defense ministry said Monday four officials at the ministry\'s intelligence agency were arrested for breaking into a university professor\'s e-mail account, local media reported. The four Defense Security Command (DSC) officers, based in Seoul and Gwanju, are charged with hacking an e-mail account of 48- year-old professor Ki Gwang-seo at Gwangju-based Chosun University, who the counterintelligence officials thought might leak confidential military information, according to Yonhap News Agency. Ki was once arrested for violating the National Security Law that bans the vaguely defined \"anti-state acts.\" Investigators have reportedly said they found no evidence the four men, who also attempted to destroy evidence of the hacking, followed orders of their superiors. Suspicious of a possible involvement of higher-ranking military officials in the incident, opposition parties here have claimed that the military is trying to cover up its illegal surveillance activities targeting civilians. The DSC is an intelligence unit tasked with collecting and protecting military intelligence.