Ex-Indian Stock Exchange CEO Chitra Ramkrishna is in police custody for suspected foul play. Image: NDTV / Screengrab

A former top official of India’s National Stock Exchange has been arrested for various irregularities that reportedly provided an unfair advantage to certain brokers.

The country’s premier investigation agency Central Bureau of Investigation on Sunday night arrested former managing director and chief executive officer of National Stock Exchange Chitra Ramkrishna in Delhi. She had led the exchange between 2013 and 2016.

She was arrested for her alleged involvement in providing certain brokers an advantage while leasing the National Stock Exchange’s co-location facility, where a third party can lease server space and other computer hardware.

The allegation is that certain brokers were able to log on to the stock exchange’s systems faster with better hardware specifications while engaged in algorithmic trading, which allowed them unfair access and advantage during the period from 2012 to 2014.

One of Ramakrishna’s subordinates, Anand Subramanian, who used to work as a group operating officer at the stock exchange, was arrested by the investigating agency last week.

Among the brokerages that reportedly took advantage of the gamed system was OPG Securities. Following a whistleblower alert in 2015, the capital markets watchdog Securities and Exchange Board of India initiated multiple investigations.

The Central Bureau of Investigation had filed a case against the promoter of OPG Securities, Sanjay Gupta, in 2018.

Ramakrishna’s arrest comes amid fresh revelations about irregularities at India’s stock exchange. Last month, investigators questioned Ramkrishna, Subramanian and Ramakrishna’s predecessor, Ravi Narain.

Last month, a report by the Securities and Exchange Board of India showed that Ramkrishna took key decisions at the stock exchange from 2013 to 2016 on the advice of a “Himalayan yogi”, whom she had never met and who instructed her to appoint Subramanian as group operating officer.