The saola, one of the rarest and most threatened mammals on the planet, has been photographed in Viet Nam for the first time in the last 15 years.
The enigmatic species was caught recently on film by a camera-trap set by the World Wide Fund for Nature (WWF) and the Forest Protection Department in the central province of Quang Nam.
"When our team first looked at the photos we couldn't believe our eyes. Saola are the holy grail for Southeast Asian conservationists, so there was a lot of excitement," said Van Ngoc Thinh, WWF-Viet Nam's country director.
"This is a breathtaking discovery and renews hope for the recovery of the species," he said.
A cousin of cattle but recalling an antelope in appearance, the critically endangered saola, dubbed the Asian Unicorn because it is so rarely seen, is recognised by two parallel horns with sharp ends which can reach 50 centimetres in length.
The last confirmed record of a saola in the wild was in 1999 from camera-trap photos taken in the Lao province of Bolikhamxay.
In 2010, villagers in Bolikhamxay captured a saola, but the animal later died.
In Viet Nam, the last sighting of a saola in the wild was in 1998.
In the area where the saola was photographed, WWF's Preservation of Carbon Sinks and Biodiversity Conservation Programme has begun an innovative law enforcement model in which forest guards are recruited from local communities.
Co-managed by WWF and the Vietnamese government counterparts, the guards help remove snares and tackle illegal hunting, the greatest threat to saola's survival.
The saola was discovered in 1992 by a joint team from the Ministry of Agriculture and Rural Development and WWF surveying the forests of Vu Quang, near Viet Nam's border with Laos.
The find proved to be the first large mammal new to science in more than 50 years and one of the most spectacular species discoveries of the 20th century.
Twenty years on, little is still known about saola's ecology or behaviour, and the difficulty in detecting the elusive animal has prevented scientists from making a precise population estimate.
At best, no more than a few hundred, and maybe only a few dozen, survive in the remote, dense forests along the Viet Nam-Laos border, according to WWF.
