BJP, which has held "jihadi forces" responsible for the killing of Deepak Rao, who was hacked to death by a four member gang on January 3, has termed Mr Kumaraswamy's charge as "irresponsible" and an attempt to mislead the investigation.
Mr Kumaraswamy, also the state JDS chief, noted that four persons had been arrested and demanded to know whether the government still had not been able to find out "who gave them supari (contract)? "
"According to my information, a BJP corporator there is involved in Deepak Rao's murder," he alleged.
The former Chief Minister demanded to know to why the truth was not being brought out about those who were behind the murder.
"What is the difficulty for this government to bring out the truth? Is there any understanding between both of them (Congress government and BJP)" he said and sought to know to whom the government was trying to protect.
Mr Kumaraswamy's charge came on a day when BJP held a dharna in the capital city, condemning the 'failure' of the Congress government in maintaining law and order.
Calling Mr Kumaraswamy a "master" in making "irresponsible" comments, BJP state President BS Yeddyurappa said his statement was far from the truth.
"I condemn his statement. Let him stop making such irresponsible comments, being a former Chief Minister. It is an attempt to mislead the investigation," he said.
Member of Parliament and BJP leader Shobha Karandlaje accused Mr Kumaraswamy of indulging in 'appeasement politics' with such statements.