Shares of Sun Pharmaceutical Industries Ltd slumped over 13 per cent on Friday in morning trade to near six-year lows, after a media report of a complaint by a whistleblower raised fresh concerns on the drugmaker's corporate governance.
At about 11.40 am, the stock was trading down 10.34 per cent or Rs 44.15 at Rs 383 on the BSE.
The complaint, sent to the capital market regulator Securities and Exchange Board of India (SEBI), is the second in over a month, according to a report.
The whistleblower complaint alleges that an Indian pharmaceutical manufacturer Aditya Medisales Ltd had transactions with Suraksha Realty, controlled by Sun Pharma's co-promoter, Sudhir Valia, the report stated.
The transactions took place between 2014 and 2017, and were worth over Rs 5,800 crore ($814.65 million), it added.
A whistleblower had approached SEBI late last year with a document alleging various irregularities by Sun Pharma, its promoter Dilip Shanghvi and others.
Sun Pharma did not immediately respond to a Reuters request seeking comment.
Shares of the country's largest drugmaker by market value recorded their biggest intra-day percentage drop since May 29, 2017.
Over 31.4 million shares changed hands, around 2.7 times Sun's 30-day trading volume average of 11.7 million shares.
Earlier this month, Sun Pharma had recalled muscle relaxtant vecuronium bromide for injection due to the presence of glass.