Tata Sons chairman N Chandrasekaran on Monday termed allegations at TCS Nashik as "gravely concerning and anguishing", and announced an investigation into the matter under a senior executive.

"The complaints and allegations emerging from the Nashik branch of Tata Consultancy Services have been gravely concerning and anguishing," Chandrasekaran said in a statement.

He also announced that a thorough investigation is underway under TCS' Chief Operating Officer Arathi Subramanian to establish the facts and identify individuals responsible for the situation.

There have been allegations of sexual harassment and forced religious conversion by eight female employees at the multinational company's office in Maharashtra's Nashik.

"This incident is being treated with utmost seriousness. Action has already been initiated against the accused employees, and the company is extending its full cooperation to the ongoing investigations," Chandrasekaran, who was leading TCS as its chief executive and managing director before his appointment as the group chairman, said.

He added that the salts-to-software group maintains a "zero-tolerance policy" towards any form of coercion or misconduct by its employees.

Appropriate and stringent action will be taken against those found guilty in the investigation, he said, adding that process improvements or other corrective measures will be promptly implemented and strictly enforced.

A local court on Monday extended till April 15 the police custody of the female HR manager of a Nashik-based IT firm in connection with case.

Assistant Public Prosecutor Aniket Awhad requested Additional Chief Judicial Magistrate JV Paliwal to extend the police custody, citing the need for an extensive investigation.

The HR manager is accused of neglecting the complaints raised by female victims.

Other arrested accused are identified as Danish Sheikh, Tausif Attar, Raza Memon, Shahrukh Qureshi, Shafi Sheikh, Asif Aftab Ansari, and Nida Khan.

After her arrest, the court remanded her to police custody till April 13.

Last week, police formed a special investigation team (SIT) to probe the complaints lodged by eight employees, who claimed that senior colleagues mentally and sexually harassed them, and the human resources department turned a deaf ear to their complaints.

Police have since arrested seven people, including the company's female HR manager.

In its first comments, TCS had on Sunday affirmed its commitment on zero tolerance in cases of harassment and informed that staff members have been suspended.

"TCS has a long-standing zero-tolerance policy towards harassment and coercion of any form. We have always ensured the highest standards of safety and well-being of our employees at the workplace. As soon as we were made aware of the matter in Nashik, we took swift action," it had said.