Speaking to a new channel, Raghavan said, "It is a very big step forward in trying to understand and unravel quite a few mysteries in the matter...I am happy that we were able to get the CM for questioning. I have to appreciate the evidence."
Raghavan pointed out that the SIT will submit its report to the Supreme Court on or before Apr 30, 2010.
He declined to go into details of the questioning of 59-year-old Modi.
Raghavan said that the petition of Zakia Jafri, wife of former Congress MP Ehsan Jafri who was killed along with 68 others in the Gulbarg Housing Society riots in 2002, was the SIT's 'bible' and questions broadly related to it.
"I have greatest concern for the victims and I have never failed to take my eye away from justice. I am conscious of the sacred trust given by the Supreme Court," the SIT chief said.