BANGKOK, Aug. 23 (Xinhua) -- Thailand's ousted premier Thaksin Shinawatra and his wife Pojaman on Thursday filed a 1.5 billion baht lawsuit against Department of Special Investigation director-general Sunai Manomaiudom on Thursday, local media reported.

    The Civil Court has set Dec. 17 to rule whether the lawsuits filed by Thaksin and his wife against the DSI merits the judicial review, according to news network The Nation.

    In the plaintiff writ prepared by his lawyer Pichit Chuenban, Thaksin contends that DSI director general Sunai has made a number of misleading statements designed to tarnish his reputation.

    Sunai's remarks were related to the investigation into the alleged equity cover-up involving SC Asset Corporation, a listed company for property development.

    Thaksin also demanded 1.5 billion baht (44 million U.S dollars) in damages from DSI.

    In a separate litigation, Thaksin assigned his lawyer Boonchaleaw Dusadee to file a criminal lawsuit against the 11-member Assets Examination Committee last Friday.

    The committee members, including chairman Nam Yimyaem, have been accused of abuse of power in raising frame-up charges related to the 2003 land purchase case.

    The Criminal Court is scheduled for Nov. 26 to rule on the merit of the judicial review.