Who was arrested and on what accusation

Russian foreign ministry spokeswoman Maria Zakharova identified the reporter as Yuki Imai from the Hokkaido Shimbun newspaper. He had been accredited with the Russian foreign ministry, she said, but was accused of "conducting espionage activities on Russian territory".

Russia's FSB said a Japanese national, whom it did not name, was arrested on Sakhalin and alleged he had worked for Japanese intelligence to collect information about Russia's defences. The security agency also published a video showing masked officers storming a hotel room, pushing a man to the floor and handcuffing him.

Custody and possible penalty

The man was flown to Moscow, where a court ordered that he be held in pre-trial detention. The report did not say when the arrest or the court hearing took place.

• •The FSB said it had opened a criminal case against the Japanese national, according to Russian news agencies citing the agency.
• •The espionage charges carry up to 20 years in prison.
• •Russian media reported he would remain in custody until 12 December.

Tokyo and Moscow react

Japan's embassy in Moscow told news agency Kyodo that the government was trying to ascertain the journalist's reported detention.

Zakharova said: "Attempts by Tokyo to use its correspondents in Russia … to gather information aimed at undermining the security of our state is regrettable." She further alleged the case was "not an isolated case".

Strained backdrop

Because Japan joined western sanctions over the war in Ukraine, Moscow lists it as an "unfriendly" country, and several citizens of countries on that list have been arrested in recent years. The two governments have also argued for decades over the status of a string of Pacific islands lying off north-east Japan and south-west of Russia's Sakhalin region. The Soviet Union seized the Kuril islands, which Japan calls the Northern Territories, at the end of the second world war, and Russia has held them ever since.

Russian president Vladimir Putin visited one of the disputed islands in August, causing an uproar in Japan. Tokyo has said it would continue implementing sanctions against Russia and supporting Ukraine.

The arrest recalls the case of US journalist Evan Gershkovich, who was arrested on espionage charges in 2023, sentenced to 16 years in prison, and released in a 2024 prisoner swap.

Imai remains in custody until 12 December pending the pre-trial detention order, while Japan's government is still trying to ascertain the reported detention.