The body of 41-year-old award-winning Bloemfontein-based journalist Junior Bonase was found next to the road on the N1 near Heuningspruit on Tuesday night.
A passer-by discovered his remains at around 23:00 and alerted the police.
According to police spokesperson Colonel Thandi Mbambo, there were injuries to Bonase's face.
"The cause of death is currently unknown and a case of culpable homicide has been registered for further investigation," Mbambo said.
A post-mortem was scheduled for Thursday to determine the cause of death.
Provincial commissioner Lieutenant General Moeketsi Sempe conveyed condolences to the family.
"We have good relations with journalists in the Free State as they support our initiatives in the fight against crime. We are saddened by the loss of such an energetic, committed journalist and will work tirelessly to uncover the cause of his death," he said.
Bonase was a senior journalist at Dumelang News, a local newspaper. He won a regional Vodacom Journalist of the Year Award in 2015 in the online category.
Last year, Bonase was nominated for a regional Vodacom Journalist of the Year Award in the investigative category.
The judges commended Bonase for "his excellent entry on the production and selling of expired goods by replacing labels".
Bonase had investigated a R74m housing project in Eiffel Village in the Joe Morolong municipality of the Northern Cape, where the contractor put up foundations and incomplete structures, and then disappeared in 2015. This investigation saw an agitated and frustrated community, and prompted government officials - including the provincial department - to try to salvage the project.
A week ago, Bonase was elected chairperson of the Free State Media Cooperative.