The rare black leopard found wounded at an estate in Nallathannniya had died while being treated at the Udawalawa wildlife centre.
The leopard was caught in a snare at an estate in Nallathanniya three days ago and was later rescued by wildlife authorities.
Police investigations already are underway into the incident.
The Department of Wildlife announced earlier this year that it had retraced the Sri Lankan Black Panther which was considered to be extinct in the country.
The Sri Lankan Black Panther is believed to have gained it’s unique characteristics due to a colour mutation.