The stock, which opened on a negative note, further declined 10.22 per cent in intra-day trade to Rs 441.95 on BSE. At 1405 hrs the scrips were trading at Rs 453.70, down 7.84 per cent from the previous close.
On the NSE, the shares fell 10.44 per cent to Rs 441.15, its lowest during the intra-day trade.
According to sources, Sebi is likely to reopen an insider trading case against Sun Pharmaceutical Industries as well as probe alleged lapses by some of its promoters and other entities in raising funds overseas.
The development comes after a whistleblower reportedly approached Sebi with a document alleging various irregularities by the company, its promoter Dilip Shanghvi and others, they added.
However, the regulator is likely to reopen the case as it has powers to reopen cases of settlement related to insider trading on various grounds.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)