Maneka Gambhir, the sister-in-law of Trinamool Congress' national general secretary Abhishek Banerjee, was stopped at Kolkata airport as she was about to travel to Bangkok yesterday. She has been summoned for questioning by the Enforcement Directorate (ED) over her alleged role in a coal smuggling case. ED officials handed her the summons at the airport itself and told her to appear before the central agency tomorrow at its office in Salt Lake, Kolkata.