A rescue team retrieved his body in a semi-decomposed form, from river Kali.
Although the police suspect suicide, the actual cause for the death would be known only after the post mortem report is made available.
Mahalingam was working in the training department which imparted knowledge on working of projects and skill development.
Earlier the media had reported that he was a scientist at Kaiga.
Nageshwar Rao, director of the Nuclear Power Corporation of India Limited, earlier dismissed reports that terrorists could have abducted Mahalingam to lay hands on classified information.