The recent killings happened at Hluhluwe-Imfolozi - KwaZulu-Natal's flagship game reserve where 11 gunshots were heard on Sunday.
Despite the white rhino being on the endangered species list with fewer than 100 on the planet in 1890, hunters are still killing them for their horns, with 139 slaughtered in the province of KwaZulu-Natal alone this year.
Wildlife rangers headed out to where the gunshots were heard at first light on Monday and discovered the slain animals.
All were dead, lying in pools of their own blood with their horns hacked off, according to News 24.
It is the latest in a string of killing sprees targeting the animal and the number of deaths could exceed 250 by the end of the year in KwaZulu-Natal.
Since 2007, more than 6,000 rhinos have been shot and butchered for their horns in South Africa.
The majority of those have come in the last four years with around a thousand being killed every year since 2013.
Poachers have been targeting the KwaZulu-Natal reserves more and more since security was beefed up at Kruger National Park in Pretoria which crosses over into Mozambique.
Among the critics of the weekend's killings was former England cricketer Kevin Pietersen who was born and raised in South Africa.