A fourth white rhino has been found shot but alive on the Tyityaba private game reserve near East London
Three rhino were found dead on Monday with their horns removed on the reserve on the Kei River.
The Hawks and the Eastern Cape Green Scorpions are investigating.
Earlier this month another two rhino were found dead on the same reserve owned by Alvin Krull and his son Frank.
Frank Krull told AlgoaFM News the wounded rhino had a flesh wound but that its chances of survival were still about 50-50.
He said Monday's discovery was made during a helicopter flight as part of the process of de-horning the reserve's remaining rhino to ensure their survival.
"Obviously there are measures being in put in place and one of them is the dehorning programme. That is how we found out there were four animals and there could be more, we don't know," he said.
However, Krull said they are going to be "ready for them (poachers)" if they come again.