Indian investigators will join their FBI counterparts on Monday to question David Coleman Headley, arrested by FBI for plotting a major terror attack in India at LeT's behest. Fresh inputs indicate that he was planning to visit Pakistan this month. The investigators from IB and RAW are also expected to probe the terror-drug nexus as it has come to light that Headley was charged by a federal court in New York in 1997 with smuggling heroin to the US. One of Headley's cousins, Farid Gilani of Philadelphia, told the Chicago Sun-Times that he spoke to Headley over the phone about a month ago. 49-year-old Headley was arrested on 18th of October along with Tahawwur Hussein Rana, a Canadian citizen of Pakistani origin, by FBI at Chicago's O'Hare International Airport before boarding a flight to Philadelphia, intending to travel to Pakistan.<br/>