Replying to queries during question hour, finance minister Yashwant Sinha said the investigation began on June 15 and after its completion, necessary steps would be taken to see that such manipulations do not recur. He said a number of tough measures have been taken since the stock scam of 1992 and SEBI had begun taking steps to ensure action was taken against such people or companies.

Four scrips saw undue volatility on the BSE which in turn shot up their prices, prompting the regulator to initiate an inquiry into the matter, Sinha said.