"The central minister said the government knew about the threat, and Gauri had sought security, but government did not give. All these, it is most irresponsible statement given by a central minister, who also is a law minister," he told reporters here.
Prasad on September 8 had shown copies of news reports on Lankesh's brother, Indrajit, claiming that she had worked for the surrender of Naxalites and asked as to why the Siddaramaiah government had not provided her security.
Siddaramaiah said if Gauri Lankesh had sought security, the government would have given it.
"If someone asks for security, we will give it... Nobody expected it. She never ever spoke about threats and sought security," he said.
Gauri Lankesh also was "a very good human being" and did not hate anyone and even talked to her opponents, Siddaramaiah said.
Replying to a query, Siddaramiah said both Maharashtra and Karnataka police were coordinating to crack the cases related to the killings of rationalists M M Kalburgi, Narendra Dabholkar and Govind Pansare.
Dabholkar was shot dead on August 20, 2013 in Pune while he was on a morning walk. Pansare was shot at on February 16, 2015 in Kolhapur and succumbed to his injuries on February 20 that year.
State Home Minister Ramalinga Reddy had also said a couple of days ago that Lankesh had never asked for security.
The 55-year-old Left-leaning journalist, a fierce critic of Hindutva politics, was shot dead at the doorstep of her house while she was returning from her office on September 5.
Her killing came in for condemnation from various quarters. The state government has formed a special investigation team (SIT) to probe the case.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)