In more trouble for Reliance Group Chairman Anil Ambani, the Enforcement Directorate has issued a lookout circular against him in connection with the alleged Rs 3,000-crore loan fraud case, sources said on Friday. The revelation was made on a day when the agency summoned the industrialist for questioning. He has been asked to appear before the Enforcement Directorate on Tuesday. A lookout circular is used to prevent individuals from leaving the country to evade prosecution. It is circulated to all entry and exit points, including airports and seaports, and officials are alerted to detain individuals against whom such notices are issued if they try to go out of the country.