This was announced by the South African National Parks (SANParks) on Tuesday.
SANParks chief executive David Mabunda said the aircraft would be used in operations against rhino poachers.
"The people making the money are syndicates and we must go after them. We need all the resources we can get."
He said the advantage provided by the plane, which was donated by the Ichowitz Foundation and the Paramount Group, would have come too late if it was procured through the usual government processes.
"We will not win this war just with the rangers with meagre resources … Do you know how difficult it is to get money from treasury for an effort like this?" Mabunda asked.
"It takes a lot of memorandums and a lot of bureaucracy and by the time money is allocated … there will be no rhino left."
He was speaking at a media briefing at the unveiling of the aircraft atSkukuza airport in the Kruger National Park.
Private sector assistance
Mabunda said partnerships with the private sector were needed as the government faced many service delivery problems and could not devote resources to fighting poaching when they were needed elsewhere.
"The cause of the rhino will rank very low in the priority of government. That is a reality."
South Africa is home to almost 80% of the world's rhino and represents the last, viable population.
He said most of these rhino lived in the Kruger National Park, which represented a "critical mass" in rhino poaching.
"Not only is the Kruger National Park home to the largest population of rhinos in the world, this national park also remains the hardest hit by poaching."
The park had lost 760 of the 1369 rhino killed since January 2010.
Mabunda said the aircraft would first be deployed in the park before being used in other national parks.
"It's critical we stem the tide in Kruger before we deploy it to other areas," he said.
The specially-outfitted Seeker Seabird, has a single propeller in its midsection and a small cabin for two personnel.
It is painted in blue camouflage, the better to blend in with the sky when viewed from the ground.
On its dashboard, in homage to its mission, is a small, stuffed rhino.
The aircraft was able to fly slowly and had surveillance capabilities in the form of a camera fitted to its body. It could accommodate a human spotter. – Sapa