Karti Chidambaram, son of former Union minister P Chidambaram, appeared before the Enforcement Directorate (ED) on Monday for questioning in the INX Media money-laundering case, officials said. The investigating officer of the case recorded the statement of Karti Chidambaram, a Congress MP from Tamil Nadu's Sivaganga, under the Prevention of Money Laundering Act (PMLA). He was last questioned in this case in October last-year.