Kim Jong Un’s slain half-brother was reportedly an informant for the Central Intelligence Agency and met with U.S. officials a number of times. The Great Successor, a new book to be published Tuesday, by Washington Post writer Anna Fifield broke news of the claim. On Monday night, The Wall Street Journal reported Kim Jong Nam, who mainly lived outside North Korea, traveled to Malaysia in February 2017 to meet with his CIA contact—said to be a “Korean-American” man who Malaysian officials suspected to be a U.S. officer. It was in Malaysia’s Kuala Lumpur International Airport that Kim Jong Nam was killed after two women smeared his face with a nerve agent. The U.S. and South Korea blamed his murder on North Korea, which denied having anything to do with it. Sources also told the Journal that Kim Jong Nam was likely a source of intelligence for China’s security services, among others. The CIA reportedly declined to comment, and Chinese officials did not respond to the Journal’s request for comment.