Close to 50 starved and sick monkeys were rescued from filthy living conditions in a South African private zoo today, and were whisked away to a care facility, an international animal rights group said.

International Primates Rescue (IPR) founder Sue Mousley said after failed attempts by the owner of Little Falls garden centre to improve the living conditions of the monkeys, the rescue team finally managed to get a court order allowing them to relocate the primates to IPR's care facility.

The monkeys were given little to no food and water while living inside filthy enclosures, Mousley said.

"They are still terribly under weight, some of them look a bit dehydrated ... the condition of most of those primates is just simply not acceptable," said Mousley.

Muldersdrift police station spokesman Hitler Ngwenya said if there was a need for a case to be opened, it would be.

"Doctors will perform their investigation in terms of determining the condition of the animals and a report will be provided," he told Reuters.

The rescue operation took place in the early hours of the morning after the monkeys were sedated.