The Central Bureau of Investigation (CBI) on February 25 arrested Anand Subramanian, a former top official of the National Stock Exchange (NSE), in connection with alleged favour dolled out to certain traders. The development comes as authorities pressed ahead with an investigation into the NSE scam case where certain private individuals and unknown NSE and SEBI officials were accused of preferential access to the NSE’s server architecture and misuse of colocation facility.