India's Minister for Science and Technology says radiation leakage at the Kaiga Atomic Power Plant was no accident.

[Prithviraj Chauhan, Science And Technology Minister]:
"Unfortunate incident in Kaiga Atomic Power plant is not a nuclear accident or even nuclear incident. It is nothing to do with the process of making electricity. Prima facie (at first sight) it appears that some disgruntled employees have tried to mix a small vile of heavy water into one particular water cooler. When the heavy water which looks like ordinary water that was mixed in a cooler and the employees who drank water from that water cooler were exposed to of heavy water and they are under medical observation."

Local police have been asked to help probe how the tritium got into the water cooler.

55 workers at the power plant tested positive for tritium contamination after drinking from the contaminated cooler.

Officials say the incident did not affect public safety.