Since Mr Busch was dismissed in 2008, the warring mother and son have faced each other in various court proceedings relating to the park, its debts and assets ownership.
Mrs Busch, who left the park after the sale was announced, says she is the only person licensed to look after the big cats.
The Ministry of Agriculture and Forestry (MAF), which has a regulatory responsibility to ensure the requirements around containment and animal welfare were met, today said Ms Busch remained the approved operator of the park.
MAF had been in talks with all parties involved over the past few days to assess whether operator responsibilities could be met under the new park ownership, verification services director Steve Gilbert said.
"The discussions we've had have been positive and an agreement has been reached between the new park owners and Patricia Busch, with the full support of MAF. This agreement ensures all responsibilities and obligations can be met."