The Securities and Exchange Board of India (Sebi) was so far focusing on trades during the fiscals 2013-14 and 2014-15 in its fight against misuse of stock market platform for tax evasion and laundering of illicit funds.However, the markets watchdog has now expanded its horizon to the previous years in this regard as there have been complaints about suspected tax evasion by way of ‘arbitrage’ between bogus losses shown in the Indian market and the ‘gains’ at offshore locations.

Such arbitrage could have taken place through trades in currency as well as equity derivatives, sources said, while adding that the modus-operandi typically involved payments being made for ‘bogus losses’ in Indian markets and ‘huge profits’ at overseas locations.

With regard to the client code modifications, sources said that the trading activities under scanner mostly took place between 2009 and 2011 after which Sebi tightened its norms to put a full-stop to such manipulations. Before tightening of the norms, the Indian markets were seeing client code modifications to the tune of `50,000-60,000 crore a month, which came down to just about `100 crore soon after Sebi’s action.

This is believed to have further come down, sources said, while adding this shows that a large-scale manipulation was taking place where brokers were making changes in the client details after execution of trades citing ‘genuine errors’.

In April 2012, Sebi had also passed an order against NSE for being “negligent in discharge of its duties” in a case of modification of client codes, but did not impose any penalty.