A lion has been spotted in Gabon for the first time in nearly 20 years, raising hopes the animals long feared extinct in the country could be returning, conservationists said on Thursday.

Lions used to roam Central Africa in their hundreds in the middle of the last century. But the population has fallen sharply due to poaching and loss of habitat.

Hidden cameras planted as part of a chimpanzee study in southeastern Gabon's Bateke Plateau have captured on tape a single male lion three times since January, said Dr. Philipp Henschel, Lion Program Survey coordinator for campaign group Panthera.

"I couldn't believe it. As soon as I could, I went there to set up more cameras," he told Reuters by phone from Libreville, adding that a new study was being launched in the hope of finding more of the big cats.

Lions are known to live a few hundred miles away in Democratic Republic of Congo and Henschel said the animal could have swum across the Congo Rriver, one of the world's largest, and traveled over to Gabon's savannah.

Male lions are often solitary roamers and can travel long distances in search of a mate.

Henschel said that researchers were considering naming the lion after Gabon's President Ali Bongo — a known lover of cats whose father, Omar Bongo, at one point had a pet tiger at home.

"We are thinking of naming the lion 'Ali' after the president as he's a cat fanatic," said Henschel.

Since Bongo was elected in 2009, Gabon has stepped up anti-poaching patrols in its 13 national parks, which are also home to elephants and gorillas. The last lion, a female, was spotted in Gabon in 1996.