NEW DELHI: Shares of IT services firm Infosys on Tuesday plummeted nearly 17 per cent, wiping Rs 53,451 crore from its market valuation, on concerns over a whistleblower complaint which alleged that two top executives of the company were indulging in unethical practices to increase short-term revenue and profits. The scrip tanked 16.21 per cent to close at Rs 643.30 on the BSE. During the day, it tumbled 16.86 per cent to Rs 638.30, the most since April 2013.On the National Stock Exchange (NSE), it plunged 16.65 per cent to close at Rs 640.The sharp fall in the scrip wiped out Rs 53,450.92 crore from the company's market valuation which now stands at Rs 2,76,300.08 crore.It was the worst-hit among the frontline companies on both sensex and Nifty.In terms of traded volume, 117.70 lakh shares of the company were traded on the BSE and over 9 crore shares on the NSE.According to reports, a complaint by a group that calls itself 'ethical employees' has alleged CEO Salil Parekh and CFO Nilanjan Roy were indulging in "unethical practices" to boost short-term revenue and profits.Infosys on Monday said the whistleblower complaint has been placed before the audit committee as per the company's practice, and that it will be dealt with in accordance with the company's whistleblower policy.In a statement on Tuesday, Infosys chairman Nandan Nilekani said the company's audit committee will conduct an independent investigation on whistleblower allegations.The committee began consultation with independent internal auditors EY, and has retained law firm Shardul Amarchand Mangaldas & Co to conduct an independent investigation, Nilekani noted in his statement to the stock exchanges.