Another eight big cats were saved from death by environmental officials and activists, the Primorye region-based Phoenix Fund said. Most of the animals were cubs orphaned by hunters.
The statistics were based on media reports about tiger-related incidents.
A list of such incidents released by the fund indicated the toll could have been as high as 25, if unconfirmed deaths were factored in that were supported by circumstantial evidence, such as abandoned cubs.
"The losses may be irreversible, given how they deplete the (species') gene pool," wrote Sergei Bereznyuk, head of Phoenix, on the fund's website.
Phoenix was founded in 2006 and is running its own tiger and leopard conservation efforts.
Tiger hunting remains a profitable business because Russia still has not outlawed trafficking of tiger derivatives, which are highly prized in Chinese traditional medicine, Bereznyuk said.
A bill outlawing such trade has been pending review in the Russian parliament since last year.
The Amur tiger was on the brink of extinction in the 1940s due to over-hunting.
Conservation efforts - supported recently by Russian President Vladimir Putin - allowed the population to reach some 450, though growth has slowed since the 1990s.