Two adult leopards and a cub were found dead under suspicious conditions in H D Kote and Nanjangud taluks on Thursday.
A five-year-old male leopard was found dead at a field in Naganahalli village in H D Kote taluk.
The village comes under Nagarahole National Park and Metikuppe wildlife range limits, on the social forest area.
Veterinarian Dr Mujeeb Rahman conducted the postmortem and the viscera has been sent for testing. The reason for the death will be ascertained after the report is available, said sources.
Similarly, a four-year-old leopardess and its cub said to be four-month-old, were also found dead in a suspicious manner at Kadaburu village, in Nanjangud taluk, on Wednesday.
Veterinarian Dr Shivakumar conducted a postmortem and said that the deaths were unnatural.
DCF, Social Forestry, Prashant Kumar said, there is suspicion over the cause of leopard deaths. The viscera have been sent to the lab in Bengaluru and results awaited, he said.