The US-based wife of Pakistani-American terrorist David Headley and his business partner have refused to answer National Investigation Agency's questions regarding the former Lashkar-e-Taiba operative's immediate family, PTI reported on Sunday. Both Headley's wife Shazia and business associate Raymond Sanders cited "privacy" clause in the US law, according to which an individual, who is not an accused in a case, can deny requests for examination by a foreign law enforcement agency. Deposing before a Mumbai court through videoconferencing, Headley had said that his wife was one of the people who congratulated him after the 2008 Mumbai terror attacks. He said that she was also aware of his plans for Denmark attacks and had booked plane tickets for him for the mission.