Central Bureau of Investigation (CBI) on Sunday questioned former chief executive officer of National Stock Exchange Ravi Narain in connection with the NSE co-location case in Mumbai, said sources.

According to sources, this comes after the CEO and former managing director of NSE Chitra Ramkrishna was also questioned by the CBI on Friday. Ravi Narain was the MD and CEO of the National Stock Exchange from April 1994 till March 2013, while Chitra Ramkrishna was the MD and CEO of the NSE from April 2013 to December 2016.