A senior official said it could have escaped late in the night.
The leopard that was captured last week after it had entered a private school in Bengaluru and injured three forest department personnel has escaped from the enclosure in Bannerghatta Biological Park, where it was caged.
A senior official said it could have escaped late in the night and the incident came to light only this morning. An operation is on to track and recapture it.
"We will come to know about it only after investigation... Once the probe is over, we will fix the responsibility and initiate action," he said.
The leopard had entered a private school near Varthur in Bengaluru on February 7 causing panic in and around the area.
However, it was tranquilised and captured after a day-long operation, during which it had attacked three forest personnel.
Meanwhile, speaking to reporters in Mysuru, Chief Minister Siddaramaiah said he would seek information from forest department officials about the leopard's escape.
"I will seek details of the animal's escape. I will talk to the forest department officials and find out the reason," he said.
Officials said there were three layers of barriers and it was difficult (for the animal) to escape by itself. ' "We will get to how the leopard escaped only after a thorough investigation," they said.