Forest Department officials said the female rhino was gunned down in Agratoli range of the World Heritage Site.
The gang of four poachers also exchanged fire from their AK-47 rifles with the forest guards though none was injured in the gun-fight, they said.
The carcass had two AK-47 bullets and eight other empty cartridges with one of .303 rifle were recovered from near the it, they said.
A rifle-silencer and an axe were recovered from a bag left behind by the poachers, the officials said.
On May 5, another adult female rhino was killed and its sawn off from Bagori Range of KNP, while on May 2, a male rhino was gunned down near Arikati camp of the range and the horn taken away.