According to inspector-in-charge of Sunabeda police station Jogeswari Behera the incident took place around 1 pm when the jawans were undergoing cross-river swimming training in the back-water of Kolab reservoir.
The 24-year old was identified as Rakesh Chandra Behera, a resident of Dhenkanal district, said police.
A case has been registered and investigation will be conducted to find out was there any foul play. The IC said.