JOHANNESBURG -- Scientists said on Tuesday they had found Angola's giant sable antelope, proving that the majestic creature had not been driven to extinction by a savage civil war.

The giant sable was known to live only in Angola and there were no confirmed sightings of the animal for at least 20 years.

Scientists speculated that it had succumbed to almost three decades of fighting between the government and UNITA rebels.

The conflict ended in April and a South African expedition led by Wouter Van Hoven of the University of Pretoria recorded three separate sightings of adult bulls and juveniles in a park about 400 km (240 miles) southeast of the capital Luanda.

"The giant sable is not extinct, but alive and well in the Cangandala National Park," the researchers said in a statement released after a two-week expedition.

"The expedition has proven that there is a viable breeding population of giant sable antelope".

The statement was released on the penultimate day of the Earth Summit, where biodiversity and the fate of the planet's many endangered species featured high on the agenda.

Male giant sables weigh up to 140kg and have elegant horns that can grow more than five feet (1.60 meters) long.

Angola's civil war raged almost continuously from 1975, decimating the southwest African country's spectacular wildlife.

Huge herds of elephants were shot for their meat and ivory by government troops and rebels alike.

Wildlife remains at risk from Angolans suffering widespread poverty and famine. But in some areas, the giant sable has a spiritual significance which gives it a measure of protection.