South Africa’s first online auction of rhinoceros horns began on Wednesday, with more than 500 kg up for bidding till Friday, CNN reported on Thursday. The auction began after the High Court in Pretoria ordered the South African Environment Minister Edna Molewa to hand over the permit for the sale of 264 rhino horns to breeder John Hume.

The Private Rhino Owners Association claimed that since the sale of rhinoceros horns was banned eight years ago, they have spent more than $100 million (Rs 640 crore) to protect the animals. They argued that without being allowed to sell the horns, breeding the animals would be financially unsustainable.

However, environmental groups have opposed the move to legalise the sale of rhinoceros horns. “The focus of conservation should be on wild rhinos,” Christina Pretorius of the International Fund for Animal Welfare told CNN. “Rhinos cannot produce enough horn on a regular basis to stem the insatiable demand.”

The South African Environment Ministry said it will heavily monitor the sale, and all horns will have to stay in the country to comply with a 40-year international ban on trade in rhinoceros horns. But Pretorius believed that this is impossible. “Frankly, we do not believe any system exists to put in place the checks and balances to prevent these horns from getting into the black market.”