On the NSE, the drugmaker's shares opened lower at Rs 416.70 apiece.

The Mumbai-based drugmaker Sun Pharma's shares fell 4 per cent on Friday, a day after the company said it has been ordered to undertake a "forensic" audit of its accounts. The firm said in a statement to financial markets late Thursday that the Securities and Exchange Board of India (SEBI) has told it to review its financial statements for the years ending March 31, 2016, March 31, 2017 and March 31, 2018. The said forensic audit is presently ongoing. The note gave no reason for the audit. However, news agency Bloomberg news had earlier reported that the development follows a whistleblower complaints on alleged corporate governance lapses that sent its share price tumbling last year.

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The allegations prompted the firm, controlled by billionaire Dilip Shanghvi, to tweak some of its business contracts to contain the crisis of confidence, according to Bloomberg.

The company is "committed to adhering to all applicable legal and statutory requirements", it said in the filing. "We will ensure that any material developments in this regard are promptly notified to all our stakeholders in line with Regulation 30 of the SEBI LODR (Listing Obligations and Disclosure Requirement) Regulations," it added.

On the Bombay Stock Exchange (BSE), Sun Pharma declined as much as 4.01 per cent to an intraday low of Rs 414.60 apiece. On the National Stock Exchange (NSE), the drugmaker's shares opened lower at Rs 416.70 apiece and fell to as much as Rs 414.45 apiece, marking a decrease of 4.01 per cent.

At 12:58 pm, Sun Pharma shares traded 2.75 per cent lower at Rs 420.05 apiece on the BSE. The Sensex was 0.75 per cent higher at that time.

