A South African policeman was shot dead by a game ranger in the Kruger National Park while searching for rhino poachers in a deadly exchange that also claimed the gunman's life, police said Sunday.

The officer was patrolling with a soldier near the Mozambican border after responding to information on potential poaching in the south of the giant park on Saturday morning.

"They came under fire and our police officer was shot and killed. The defence force member retaliated and fatally wounded the shooter," said police spokesman Vish Naidoo.

"It has emerged that the shooter was in fact an on-duty game park ranger. We opened an inquest and that is primarily to determine the circumstances and the cause of the incident."

The world famous game reserve is the front line of South Africa's rhino poaching bloodbath which claimed 448 animals last year.

The animals are slaughtered to fuel Asian demands for their horns which is used in the false belief of it having powerful healing properties.

The latest poaching toll released on April 19 was 181 so far this year with 111 alone in Kruger despite a scale up of anti-poaching efforts seeing the army move into the park and ramped up security on private farms.

A total of 113 people have been arrested this year, with arrests since the escalation of the poaching onslaught in recent years including vets and game farmers. Four Kruger staff were arrested in February.

A game ranger was killed in September after being mistakenly shot by his colleagues while chasing suspected poachers in the Umfolozi reserve in the eastern KwaZulu-Natal province.