ADRs of Infosys were down 15.7 per centat $8.91 in premarket trading on the New York Stock Exchange.

US-listed shares of Infosys fell nearly 16 per cent in premarket trading on Monday after the software services exporter said it had received whistleblower complaints alleging "unethical practices" by the company's executives.

The company issued a statement after The Economic Times reported that an anonymous group sent letters to Infosys' board and the US Securities and Exchange Commission alleging that the company was taking "unethical" steps to boost short-term revenue and profit.

The group alleged that Chief Executive Officer Salil Parekh was bypassing reviews and approvals for large deals, the ET report said.

"In large contracts like Verizon, Intel, JVs in Japan, ABN AMRO acquisition, revenue recognition matters are forced, which are not as per accounting standards," the report said, citing cited the letters.

Reuters was not able to independently review the letters.

The complaints follow a strong quarterly show by Infosys, which raised the lower end of its annual revenue forecast on upbeat demand for its digital services from Western clients.

"(The complaints) have been placed before the audit committee as per the company's practice and will be dealt with in accordance with the company's whistleblower policy," Infosys said in a filing

ADRs of Infosys were down 15.7 per cent at $8.91 in premarket trading on the New York Stock Exchange. Domestic markets were closed on Monday for a holiday.