The Enforcement Directorate has questioned former NSE Managing Director Chitra Ramkrishna on five key points among others, which are yet to be unanswered.
ED asked about the alleged manipulation of the NSE when Ramkrishna was at the helm of affairs at the bourse, said officials privy to the investigation.
The federal agency had asked how the co-location scam could take place when Ramkrishna was holding the post of CEO and MD of the NSE.
The investigators also asked about the recent disclosures that came to the fore in relation with the alleged governance lapses in appointing Anand Subramanian as the chief strategic advisor and his re-designation as group operating officer and advisor to Ramkrishna when she was the NSE MD.
Subramanian, NSE's former group operating officer, was arrested by the CBI in Chennai on 24 February 2022.
The ED investigators also asked about the charges of brokers being given preferential access to the NSE's trading system in the form of a co-location facility through which they bought "rack space" for their servers.
The CBI investigation has revealed that these traders obtained faster access to the Exchange's data feed.
According to the officials, the interrogation to disclose the said key points was concluded at the Tihar Jail in Delhi.
Ramkrishna is being lodged in jail after she was arrested by the CBI on March 6 in the alleged NSE co-location scam.
The federal agency has also recorded Ramkrishna's statement each time under the criminal sections of the Prevention of Money Laundering Act (PMLA).
A total of three Central agencies, including ED, CBI and Income Tax Department, are investigating the irregularities at the National Stock Exchange.
The ED case is based on a CBI FIR registered in 2018 where a brokerage firm was accused of manipulating the bourse in connivance with NSE office bearers.
ED also conducted searches at nine locations across Delhi and Gurgaon, last month, in connection with its money laundering probe into the alleged case.
CBI arrested Ramkrishna and Subramanian early this year and they are currently lodged in jail.
A chargesheet has also been filed against them in court by the CBI.
The Securities and Exchange Board of India (SEBI) had launched its probe into the co-location matter in early 2015 after it was brought to light by a 'whistle-blower' that some brokers were allegedly getting preferential access through the said facility, early login and 'dark fiber' which can allow the trader a split-second faster access to data feed of an exchange.
As part of this facility, brokers could place their servers within the stock exchange premises giving them faster access to the markets.
Ramkrishna got elevated as MD and CEO of NSE on 1 April 2013 and left the bourse in 2016.
The action by the central agencies against Ramkrishna, Subramanian and others was renewed after a report of market regulator SEBI came on February 11.
(With ANI inputs)
