Two employees of Tata Consultancy Services (TCS) have been arrested for their alleged involvement in unauthorised access to the database of the Gemological Institute of America (GIA) and altering data related to diamond grading.

The action against the two employees comes in the wake of an FIR filed by India's largest IT firm in Gujarat after it found the involvement of the two in tampering with the database of GIA that affected more than 1,000 diamond grading reports.

Earlier this month, TCS -- which offers database services to the GIA -- learnt about the tampering after it discovered "discrepancies in grading information" through internal controls. The investigation was initiated by the GIA along with TCS.

"TCS takes any integrity issues very seriously. In line with our policies, we have filed an FIR and terminated services of the concerned associate after investigations," a TCS spokesperson told The Economic Times.

One of the two employees who were taken into custody had quit his job before the investigation was over.

"The investigation indicates that one or more former employees of TCS made these unauthorised changes. The individuals, acting at the behest of other parties unrelated to GIA or TCS, gained unauthorised remote access to alter grades before reports were printed and sent to clients," the GIA had said in a statement last week.

The GIA said "it was cooperating with law enforcement officials in India".

"GIA is very appreciative of the efforts made by TCS to identify the affected reports and for their open and transparent cooperation during the investigation," the institute said in a statement.