"Dr Kalburgi was shot dead at his Kalyangar residence in Dharwad around 8.40 AM," Dharwad Police Commissioner Ravindra Prasad told PTI.
Kalburgi (77) was shot in his head after he opened the door of his house in the morning, Prasad said.
Asked how many bullets he sustained and who was behind in the attack, Prasad said police are awaiting details.
Kalburgi was rushed to a hospital where he was declared dead, he said.
He was a scholar, academic and researcher who had landed in controversy on several occasions for his remarks on religious, social and other issues.