The Enforcement Directorate on Thursday filed a money laundering case against former Mumbai Police Commissioner Sanjay Pandey and former chiefs of the National Stock Exchange Chitra Ramkrishna and Ravi Narain in connection with a case of allegedly tapping phones of stock exchange employees, PTI reported, citing officials.

The agency also arrested Ramkrishna, who was in judicial custody in connection with the alleged co-location scam. A Delhi court has sent her into the Enforcement Directorate’s custody for four days.

The co-location scam pertains to allegations of preferential access to the National Stock Exchange’s trading platform that allowed certain brokers to trade before the markets opened. The first FIR in the case was filed in 2018.

Ramkrishna and Narain, both former managing directors and chief executive officers of the stock exchange, have already been booked for the scam by the Central Bureau of Investigation. Pandey and the former National Stock Exchange bosses were booked by the CBI in the phone tapping case on July 8.

The new case is linked to alleged phone tapping of employees of the National Stock Exchange during the period when the co-location scam took place. The CBI has alleged that Pandey had set up a company called iSec Securities, which was used for electronic surveillance of the employees.

Pandey was questioned by the Enforcement Directorate on July 5 for its investigation into a money laundering angle in the co-location scam. He had retired as Mumbai Police commissioner on June 30.

Enforcement Directorate officials said that the agency found evidence of secret phone surveillance during the questioning. The agency then informed about the development to the Union home affairs ministry which asked the CBI to probe the case, the officials added.

Earlier this month, The Indian Express had reported that the CBI is looking into the functioning of iSec Securities that was set up in 2001.

iSec Securities was one of the firms tasked to conduct security audits at the National Stock Exchange between 2010 to 2015, during which the co-location scam allegedly took place. The company did not alert the stock exchange that its servers were compromised, the CBI has alleged.