IT services firm Infosys Ltd. (NYSE: INFY) reported that it found no evidence to back up anonymous whistleblower claims made last month against the company, the company said in a letter on Saturday to the National Stock Exchange of India Ltd.

“With respect to the anonymous complaints, there is no prima facie evidence that the company has received until date to corroborate any of the allegations made,” the company wrote in the letter.

It still has retained the law firm of Shardul Amarchand Mangaldas & Co. to investigate the allegations.

Last month, Infosys announced the claims, and said the US Securities and Exchange Commission had also begun an investigation. Infosys said it will cooperate with the SEC.

The complaints related to alleged unethical practices, some involving the CEO's travel.