The Securities and Exchange Board of India (Sebi) has reportedly clamped down on a large number of organised syndicates who set up "shops" to convert black money into legitimate-looking funds through the stock market platform.

Quoting Sebi chairman UK Sinha, PTI reported on Wednesday that the regulator has acted against nearly 900 firms as it suspects tax evasion to the tune of at least Rs 6,000 crore. It has also referred these cases to the Central Board of Direct Taxes (CBDT) under the Income Tax Department for further investigation.

"We have banned more than 900 entities and my guess is that the tax avoidance that has happened in these cases is more than Rs 5000-6,000 crore... We have given all the details to the CBDT and we have told them that they should probe them," the Sebi chief told PTI.

He said Sebi is trying to curb money laundering and other market-related manipulations separately, adding there are always people in any country or in any market who try to find loopholes and take advantage.