Shares of Aurobindo Pharma Ltd fell as much as 4 per cent to Rs 764.55, their lowest since November 13, as according to a media report, the company is facing a class action lawsuit in the US over carcinogenic elements in its blood pressure drug.

The drugmaker has been named in the lawsuit for alleged contamination of its irbesartan active ingredient (API) used in the treatment of high blood pressure, the report added.

The company did not immediately respond to Reuters' request for a comment. More than 1.7 million shares changed hands at 0457 GMT, compared with 30-day average of around 2.6 million.