The claims against the mine were made after rescuers retrieved the fourth body and were searching for the fifth miner who was yet to be found, the Sowetan newspaper reported on Wednesday.
The paper reported that five mineworkers, according to the company, entered an abandoned area underground at Kloof Ikamva shaft near Westonaria in southwest of Johannesburg on Monday.
Sibanye said a closed-off section of the shaft had poor ventilation, making it dangerous for any mining activities since 2015.
A mineworker who worked with the deceased workers alleged that his group of five was forced to go and into the section of the shaft by their "shift boss" [supervisor], who unfortunately was one of the four dead miners.
"Initially, the group consisted of six. Among them was the mine overseer, the supervisor and the safety representative. The representative refused to go into that section of the shaft because he said it was too hot and the temperature in there was 37 degrees centigrade," the daily quoted the miner as saying.
The miner accused the mining company, which has a poor safety record, of placing more value on profits than the lives of its miners.
"That section of the shaft was closed off in 2015 after a mineworker died. The mine knows that it [the shaft] is not operational and yet they sent that group in there," he said.
He said as recent as two weeks ago, another group was ordered to enter the same section but the miners refused, citing safety problems.
Another miner said instructions to enter the mine on that fateful Monday came from the mining company, which has denied the charge.
"The shift boss forced them to go in there. But it is not his decision to make, it came from the mine. Workers cannot enter prohibited areas without the consent of the mine," the unnamed, who feared reprisals, added.
He alleged the company had a reputation for flouting safety regulations in favour of making money at the expense of the poor miners.
"If you are told to do something and you refuse, you are threatened with dismissals. Those guys had no choice, even their shift boss (who died with them)," the miner said.
The mining company's Thabisile Phumo declined to comment on the allegations but said a thorough investigation would be conducted to determine why the group of miners were in the closed section.
"The miners were on duty at the time of the incident. We do not know what prompted the miners to go to that closed-off section," Phumo said.
According to the National Union of Mineworkers' spokesperson, Peter Bailey, a total of 45 miners in the country have died since January, while Sibanye alone accounted for 19 of those deaths.
"We understand that there was an intention to reopen the part of the shaft because there doesn't seem to be anyone who knows what those miners were doing there."