Police suspect that the victim, Ashok, could have been killed over some land dispute.
"He is a Congress worker. At one time, he used to be head of Railway Road Market Association here and probably also had a jewellery outlet there.
He was attacked by three assailants when he was on a morning walk in a park," Rohtak SSP Shashank Anand told PTI.
The SSP said that Ashok was rushed to PGIMS at Rohtak, where he was declared dead on arrival.
Asked what could be the motive behind the killing, he said, "We have got some information that he had some land dispute with his brother.
There is also information that he had a land dispute with another party. We are trying to develop these pieces of information as we investigate the case". He said that a case under relevant provisions of the law has been registered in connection with the incident.