Known as Kuzya, the 330-pound male cat swam to the Taipinggou Nature Reserve in China via the Amur River earlier this month.
He is one of three grown cubs released with tracking collars by the Russian president in May, after they were rescued from the wild a year earlier.
Chinese border guards apparently saw the tracks of a large animal near the damaged henhouse, along with feathers and blood, and Kuzya is the No. 1 suspect.
Siberian tigers are endangered with less than 500 estimated to be left worldwide, but they are very valuable on the Chinese black market. Park rangers are reported to have been checking for hunting traps, and alerting local farmers in the hope that Kuzya won’t be poached.