HD Kumaraswamy was heard speaking to most likely to a senior police officer.

Highlights Kumaraswamy heard reacting to killing of local JDS leader on phone

Says "kill miscreant mercilessly... there would be no issue"

Has clarified that it was not an order he issued as Chief Minister

Karnataka Chief Minister HD Kumaraswamy has landed in a controversy after being caught on tape telling someone - most likely a senior police officer - to "mercilessly kill" to avenge the killing of a local leader of his party, the Janata Dal Secular or JDS.

"He (H Prakash) was a good man. I don't know who killed him in this way. Kill the miscreant mercilessly in a shootout. There would be no problem," he is heard saying in video clips recorded by local journalists.

His predecessor BS Yeddyurappa of the BJP said he should apologise for the comment.

Weathering criticism that has been sharp and widespread, the Chief Minister called his words an "emotional" reaction.

"It was not my order, I was emotional at that moment. They (the killers) are the reason for two murders and they were in jail. They came out on bail two days ago and killed another person...this is how they are misusing bail," Mr Kumaraswamy said on Monday.

Leaders close to the Chief Minister said he was shocked to hear about the killing and it was just an outburst.

Prakash, a local leader of the Janata Dal Secular, was hacked to death in Mandya.

The JDS leader, H Prakash, was hacked to death on Monday around 4.30 pm in Mandya in south Karnataka, reportedly by four men on motorcycles who chased his car down, forced it to stop and attacked him with machetes.

They left him slumped inside the SUV, drenched in blood. He was taken to the Mandya Institute of Medical Sciences, where he died.

The Chief Minister's office later sent a statement: "Prakash was a loyal party worker. The district police have been directed to take steps to arrest the accused."

Mr Kumaraswamy became chief minister of Karnataka in May after forming an alliance with the Congress following elections that threw up a hung verdict.