Last month Karnataka Chief Minister Siddaramaiah said he would personally monitor the probe into the death of Mr Kalburgi, who was shot dead at his home in Dharwad.
Six Kannada writers today registered their protest against what they said was slow progress in the investigation of the murder of rationalist writer MM Kalburgi and returned awards conferred by the government.
The writers returned their BMTC Aralu Sahitya awards to the president of the Kannada Sahitya Parishat on Saturday.
The writers have said if the case is solved by early November, they would accept the award once again.
MM Kalburgi, 77, was shot dead at his home in Dharwad in north Karnataka in late August and police have so far made no arrests.
It is believed that investigators are looking at possible links between this killing and the murder of two other rationalists, Narendra Dhabolkar and Govind Pansare in Maharashta.
Anti-superstition activist Narendra Dabholkar, was shot dead in Pune while he was out for a morning walk in August 2013.
Social activist and veteran CPI leader Govind Pansare, who was holding agitations against toll tax among other issues, was shot dead in similar circumstances in Kolhapur, Maharashtra In February this year.
Last month Karnataka Chief Minister Siddaramaiah said he would personally monitor the probe into the death of Mr Kalburgi, who was shot dead at his home in Dharwad.
The chief minister has also announced a cash reward for Rs 5 lakh for any information that leads to the arrest of the killers.