The Infosys board has accepted Vishal Sikka's resignation with immediate effect. NDTV reports that Dr Sikka cited "personal" attacks as one of the reasons for his surprise resignation.

"In his notice of resignation to the board, Dr Sikka reiterated his belief in the great potential of Infosys, but cited among his reasons for leaving a continuous stream of distractions and disruptions over the recent months and quarters, increasingly personal and negative as of late, as preventing management's ability to accelerate the company's transformation," Infosys said in a statement.

"The board understands and acknowledges Dr Sikka's reasons for resignation, and regrets his decision. In particular, the board is profoundly distressed by the unfounded personal attacks on the members of our management team that were made in the anonymous letters and have surfaced in recent months," Infosys added.

"As the board has previously stated, a series of careful investigations found no merit to the unsubstantiated and anonymous allegations that had been asserted. The Board denounces the critics who have amplified and sought to further promote demonstrably false allegations which have harmed employee morale and contributed to the loss of the company's valued CEO," the board further said.