This as Thandi Mbambo, the spokesperson of the police in the Free State, confirmed to OFM News that the results from the pathology lab came back as inconclusive on Thursday.
This despite the fact that he was found with injuries to his face. He was discovered by a passer-by, who alerted the police.
Police will be running more tests on his body.
Mbambo in a statement revealed that a preliminary investigation showed that the deceased was on the way to Parys to follow up on a story.
A post-mortem was conducted on Thursday, which came back inconclusive and will be repeated on Monday 27 May 2019 in Bloemfontein.
Other samples have been referred for forensic tests.
Meanwhile, a case of culpable homicide has been registered for further investigation.
No arrests have yet been made and police appeal to anyone with information on what could have transpired leading to the death of Bonase, to please contact Detective /Sergeant Lebohang Dunster at 082 466 6819 or call Crime Stop at 08600 10111.
Tributes for him continue to pour in following his death on Tuesday evening.
Bonase was a senior journalist at Dumelang News, a local publication in Bloemfontein, and also worked for several media houses across the province.
His death comes barely a week after being elected chairperson of the Free State Media Cooperative (FSMC) - whose mandate is to empower and develop print media in the province.