(Reuters) - Shares of India's Sun Pharmaceutical Industries Ltd (NS:SUN) slumped over 13 percent on Friday to near six-year low, after a media report of a complaint by a whistleblower raised fresh concerns on the drugmaker's corporate governance.
The complaint, sent to the capital market regulator Securities and Exchange Board of India (SEBI), is the second in over a month, according to the report by Moneylife magazine.
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 58 billion rupees ($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 as of 0453 GMT, 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.
($1 = 71.1960 Indian rupees)