India, Nov. 16 -- No one seems to have noticed Dr. Mohammad Umar Un-Nabi's quite exit from the Al-Falah Medical College in Faridabad on October 30. Ten days later, Nabi became the focus of a nationwide investigation after it emerged that he was driving the Hyundai 20 that exploded on a busy arterial road near the Red Fort on the evening of November 10, killing at least 12 people.

Investigations have now revealed that the doctor, part of an alleged white-collar terror network that included several doctors, was staying in a bare, rented room, in a house in Haryana's Nuh, 82kilometres from Delhi, till the day before the blast. Senior investigators from the National Investigation Agency, which is in charge of the investigation, and the Jammu...