Ustin, a Siberian tiger released into the wild by Russian President Vladimir Putin, is suspected of raiding a goat farm in northeast China's Heilongjiang Province, local authorities said on Tuesday.

Experts on Siberian tigers believe it was Ustin who attacked the goats, killing two and with another three missing on Heixiazi Island in Fuyuan county of Heilongjiang on Sunday night, sources from the county told Xinhua.

Footprints and other traces left near the goat house belonged to Ustin, said Zhu Shibing, a wildlife protection expert from the Northeast Forestry University.

Xinhua correspondents saw the dead goats in the house. A hole the size of a human finger was clearly visible on each goat's head, Zhu said, their skulls have been crunched, which shows the power of the tiger's jaws.

"Our monitoring data and this attack all tell that Ustin is in good physical condition, and has a large range of activities on Heixiazi Island," Zhu said.

He warned nearby villagers not to get close to the tiger or throw food to it if they see Ustin.

About two years ago, Russian experts rescued five tiger cubs. Putin released three of them in early summer. In October, two of them, Kuzya and Ustin, were found, thanks to their tracking devices, to have made their way to China.