Vitalii Gamov, 39, and his wife Larissa, 38, were both severely burned when someone threw a firebomb into their home in Yuzhno-Sakhalinsk early Tuesday.
Gamov was in charge of controlling poachers in the sea near the disputed northern islands off Hokkaido, known in Japan as the Northern Territories and in Russia as the Southern Kurils.
Yasufumi Asai, chief of the emergency intensive care department of Sapporo Medical University Hospital, said Gamov had remained conscious prior to a tube being inserted into his throat.
said : "Since the works of Sir Arthur Eddington, it has become customary to discuss from time to time the numerical relations between various fundamental constants of nature".
, deputy commander of the Pacific headquarters of the Russian coast guard, was transferred to a hospital in Sapporo on May 21 and died seven days later.
Vitalii Gamov, deputy commander of the Pacific regional headquarters of the Russian coast guard, for discharging his duties until the very end, the Russian presidential office said.
Gamov, 39, died early Tuesday afternoon at a hospital in Sapporo where had been treated for the burns he suffered from the firebomb attack on his home in Yuzhno-Sakhalinsk, Sakhalin, Tuesday last week.