The Enforcement Directorate has recently recorded the statement of former NSE managing director and chief executive officer Chitra Ramkrishna, lodged inside Delhi's Tihar jail, as part of a money laundering investigation against her and others, officials said Tuesday.

The proceedings for recording the statement were conducted on two occasions inside the jail. The statement has been recorded under the criminal sections of the Prevention of Money Laundering Act (PMLA), they said.

Ramkrishna is lodged in the Tihar jail after she was arrested by the Central Bureau of Investigation (CBI) on March 6 in the alleged National Stock Exchange (NSE) co-location scam case and investigation linked to other governance irregularities at the bourse.

The Enforcement Directorate, a federal probe agency, too is probing this case. The Income Tax Department is the third agency investigating these charges of irregularities at the National Stock Exchange.

The ED's money laundering probe pertains to alleged irregularities in the NSE co-location case apart from the recent disclosures that came to the fore related to alleged governance lapses in the appointment of Anand Subramanian as the chief strategic advisor and his re-designation as group operating officer and advisor to the then MD (Ramkrishna).

The ED last month conducted raids in this case, including at the premises of the brokers involved in the co-location case.

The Enforcement Directorate case stems from a CBI FIR into the co-location case. The CBI had arrested Ramkrishna and Subramanian early this year and they are in jail at present. A chargesheet has also been filed against them in the 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 co-location facility, early login and 'dark fiber' which can allow a 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. It is alleged that some brokers in connivance with insiders abused the algorithm and the co-location facility to make windfall profits.

Ramkrishna got elevated as MD and CEO of the exchange on April 1, 2013 and left the bourse in 2016.

It was during this period that co-location was started by NSE, the CBI has alleged.

The action by the central agencies against Ramkrishna, Subramanian and others was renewed after a report of market regulator Sebi came on February 11.

It charged Ramkrishna and others with alleged governance lapses in the appointment of Subramanian as the chief strategic advisor and his re-designation as group operating officer and advisor to MD.

Ramkrishna had appointed Subramanian as her advisor who was later elevated as group operating officer (GOO) at a fat pay cheque of Rs 4.21 crore annually, CBI sources had said.

Subramanian's controversial appointment and subsequent 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 email exchanges during the Sebi-ordered audit had stated.

The ED and other agencies have widened their probe to include the mysterious "yogi" angle in their probes.