Central Bureau of Investigation (CBI) conducted a coordinated search operation on Saturday at over ten locations across different cities in connection with the NSE co-location scam case, officials said.

They said the search operation will include brokers in Mumbai, Gandhinagar, Delhi, Noida, Gurugram, and Kolkata, among other places. According to officials, the central agency has filed a charge sheet in the matter against former NSE CEO and MD Chitra Ramkrishna and group operating officer Anand Subramanian.

The investigation has found that between 2010 and 2015, when Ramkrishna was running the NSE, OPG Securities, one of the defendants in the FIR, connected to the secondary POP server on 670 trading days in the "Futures and Options" sector.

During the tenures of Ramkrishna and Subramanian, the CBI kept an active investigation into claims of preferential access offered to specific brokers by NSE officials and undue benefits earned from it.

According to officials, Ramkrishna, who took over from former CEO Ravi Narain in 2013, appointed Subramanian as her advisor, who was thereafter promoted to group operating officer (GOO) with a salary of Rs 4.21 crore per year.

A review of Subramanian's e-mail exchanges during a SEBI-ordered audit revealed that an anonymous individual, whom Ramkrishna claimed was a formless mystery "yogi" (mystic) dwelling in the Himalayas, guided her contentious nomination and subsequent elevation, besides crucial decisions.

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