Zhu Jiang, head of the WWF NE-China Program Office, said Saturday that the photos, taken earlier this month, are the first images of a wild Siberian tiger taken in the mountainous area.
He said the evidence confirms the mountains' role as an important habitat for the endangered species, and reinforces the need for local authorities to tighten protection measures, especially improving animal rescue efforts.
The agency estimates that there are fewer than 20 wild Siberian tigers remaining in China. They live in Heilongjiang and Jilin provinces.
Zhu said animal traps still pose a major threat to the safety of wild Siberian tigers, as a WWF survey found an average 1.6 traps for every 10 kilometers in its nature reserves last winter.
A wild Siberian tiger was found dead with a trap around its neck in the city of Mishan, Heilongjiang, in October.
"The WWF hopes to cooperate with local governments to protect Siberian tigers and restore their habitats," said Zhu. "We aim to help double the population of wild Siberian tigers in China by 2022, the next Year of the Tiger," he said.