The carcass was first sighted by tea workers who went to report for work in the morning, police said.
The forest department was informed and the carcass was taken away by its workers.
Forest department sources said post mortem would be conducted on the leopard to find out whether the animal was killed by poachers as feared by the tea workers and the locals.
A number of leopard deaths have been reported from Binnaguri, Buxa and Gorumara ranges in recent times.