In retaliation for expelling a Japanese diplomat from Russia on suspicion of espionage, Japan has expelled a Russian consul from the country.

The diplomat working at the consulate in Sapporo in northern Japan has six days to leave Japan, Foreign Minister Yoshimasa Hayashi said in Tokyo on Tuesday.

The Kyodo news agency reported that Russia's ambassador had been summoned to the Foreign Ministry and informed.

Hayashi criticized the arrest of the Japanese diplomat in the eastern Russian city of Vladivostok, who was violently detained and blindfolded despite having done nothing illegal.

The treatment and interrogation of the diplomat had been a serious violation of international law.

After the expulsion, the consul returned to Japan last week.

Russia's domestic secret service FSB had announced that the diplomat had been caught "in the act" of receiving secret information about the effects of Western sanctions, among other things, for a fee.