Sanjay Gupta, the managing director of OPG Securities, has been detained by the Central Bureau of Investigation (CBI) in connection with the NSE co-location issue. Recently, the central agency searched at least 10 more locations, including Gupta's brokerage, as part of the investigation.

According to reports, the CBI was able to uncover a cartel that reportedly 'aided Gupta in approaching Sebi officials' between 2015 and 2018 when the capital markets regulator was investigating the NSE algorithm scandal.

According to a person with knowledge of the situation, "the searches and the inquiry have suggested that there is a Mumbai-based syndicate that might have helped Gupta in reaching out to Sebi officers who were conducting the investigations." His interrogation is required to determine whether he tried to  pay any bribe, made an offer or actually paid the bribe." OPG Securities, unknown officials of the Securities and Exchange Board of India (Sebi) and National Stock Exchange (NSE) have also been named in the first information report registered by the agency in 2018.