Chitra Ramkrishna, the former chief executive officer of the National Stock Exchange of India (NSE), was arrested late on March 6 in the NSE co-location case, CNBC TV18 reported.
Officials confirmed to the news channel that she was arrested from Delhi, a day after a court in the national capital dismissed her anticipatory bail plea.
The Central Bureau of Investigation (CBI), which is probing the co-location case, had argued against her pre-arrest plea, claiming that she was "evasive" and not cooperating with the investigating officials.
The agency conducted Ramkrishna's questioning for three days during which she allegedly did not give proper responses to the investigators, the officials said on March 5.
On February 25, the CBI arrested former NSE group operating officer Anand Subramanian after expanding its probe into a co-location scam in the exchange, following ''fresh facts'' in a SEBI report that referred to a mysterious ''yogi'' guiding the actions of Ramkrishna.
Subramanian was allegedly referred to as the ''yogi'' in the forensic audit, with whom Ramkrishna is accused of sharing confidential information. However, the Securities and Exchange Board of India (SEBI), in its final report, had rejected the claim.
Ramkrishna, who succeeded former NSE CEO Ravi Narain in 2013, had appointed Subramanian as her advisor. He was later elevated as the GOO at a fat pay cheque of Rs 4.21 crore per annum.
Subramanian's controversial appointment and later elevation, besides crucial decisions, were guided by an unidentified person, who Ramkrishna claimed was a formless mysterious ''yogi'' dwelling in the Himalayas, a probe into her e-mail exchanges during the SEBI-ordered audit showed.
Ramkrishna had left the NSE in December 2016.
On February 11, the SEBI charged Ramkrishna and others with alleged governance lapses in the appointment of Subramanian as the chief strategic advisor and his re-designation as GOO and advisor to the MD.
SEBI has levied a fine of Rs 3 crore on Ramkrishna, Rs 2 crore each on NSE, Subramanian, former NSE MD and CEO Ravi Narain, and Rs 6 lakh on V R Narasimhan, who was the chief regulatory officer and the compliance officer.
The CBI, which was probing the co-location scam since 2018 against a Delhi-based stock broker, swung into action after the SEBI report that showed alleged abuse of power by the then top brass of the NSE.
The agency expanded its probe and grilled Ramkrishna, Narain and Subramanian in connection with the scam.
The central probe agency booked stock broker Sanjay Gupta, the owner and promoter of Delhi-based OPG Securities Private Limited, in 2018 for allegedly making gains by getting an early access to the stock market trading system, the officials said.(With PTI inputs)