Patrolling forest personnel recovered the carcass last night after they were alerted about the possibility of a fight between animals in the park, KNP Divisional Forest Officer Dibyadhar Gogoi said.
Forest personnel suspected that there was something amiss in the park after they heard sounds of animals and noticed unusual behaviour among other animals since Friday evening.
"We suspected something was wrong among the big animals like tiger, rhino and elephant. Our men were put on alert since then. A clue that there was a fight between the two elephants was found yesterday with the recovery of the carcass. The elephant was killed on Friday evening", he said.
The carcass was sent for postmortem.
Gogoi said the incident was rare and forest officials were looking into it.
Meanwhile, a group of four elephants came out of the Mikirjan camp of the park under Kohora range and injured two persons, damaged seven houses and the Japori Pathar Anganwadi Centre.
The injured villagers have been identified as Bubu Baruah and Akon Das and they have been admitted to the hospital.