Kovacevic consulted IBO officials who confirmed Berridge is still fighting for the IBO world light heavyweight title. If he wins the bout, he will be crowned champion.
However, Oosthuizen must vacate the title if he is successful because he was over weight, with 20 per cent of his purse going to Berridge and 10 per cent to the South African boxing commission.
Kovacevic said he felt unnerved by the confrontation.
"It felt like deliberate intimidation, which I found highly unprofessional. Ultimately we must come back to the fact that we made weight easily. We've done our job and it's up to Tommy's team to do theirs .
"We've been constantly reminded that Johannesburg isn't a safe place and, in light of some of the tension today, will be hiring an armed security detail.
"Regardless of the drama, we are fighting for the world light-heavyweight title, against the same opponent, who will now carry an advantage in not having drained himself to make the agreed weight.
"Rob is ready. We know we are up against it, but we haven't come to the lion's den for nothing."NZME.