Moscow has expelled a Japanese man for attempts to collect "classified information," the Russian Foreign Ministry said on January 27.
According to the ministry, an unidentified Japanese national, who was in Russia on a journalistic visa, was detained on December 25 while trying to collect data linked to Russia's military potential in the Far East.
The ministry said the man was warned about "the inadmissibility of his actions," ordered to leave the country, and left Russia the following day.
The ministry also summoned a Japanese diplomat and handed him a note of protest over the incident.
The ministry's announcement comes a day after Japanese police arrested a former employee of Japanese telecom and energy giant Softbank for allegedly stealing proprietary information from the company and giving it to Russian officials.
Yutaka Araki, 48, is suspected of obtaining "trade secrets from a computer server at a telecommunication-related company on February 18 last year, in violation of Japan's unfair competition prevention law," Tokyo police said in a statement, without disclosing the firm.
Meanwhile, media reports in Japan said it was major mobile carrier SoftBank Corp, a unit of the SoftBank Group.
Police suspect Russian trade officials at Moscow's mission in Tokyo were involved in espionage, media reports said.
The Russian embassy has described the media reports as "regrettable" and "cheap spy allegations."