At least three Russian diplomats, among the hundreds who have been expelled from European Union member states or put on the "black list" since the beginning of the invasion of Ukraine, are now accredited representatives in Serbia, Radio Free Europe (RFE) reported on Monday.

In the months following Russia's unprovoked invasion of Ukraine last year, hundreds of Russian diplomats were expelled from EU countries, with several countries citing alleged espionage as the reason for their expulsion or blacklisting.

At least three of those diplomats are now accredited to Serbia, including two with ties to Russian intelligence services, RFE said, citing its months-long investigation.

The fourth diplomat, currently in the Russian embassy in Belgrade, left the Russian diplomatic mission in Helsinki two months after Finland announced that it would expel the country's diplomats in response to Russia's invasion of Ukraine.

Russia has stepped up its diplomatic presence in Serbia following a wave of EU diplomat expulsions last year, and the Serbian Foreign Ministry now has 62 accredited diplomats on its list, compared to 54 in March 2022.

Unlike most European countries, Belgrade did not impose sanctions on Moscow after the start of the invasion of Ukraine, and while Serbia aspires to join the European Union, President Aleksandar Vucic and the government of Ana Brnabic strive to maintain traditionally strong ties with Russia, explaining this as national and state interests.

In addition to energy dependence on Russian gas, Serbia and Russia share an Orthodox Christian heritage, and Moscow has supported Belgrade in numerous disputes with the West. At the same time, Russia is among the countries that do not recognise Kosovo's independence and supports Serbia's efforts to block Kosovo's membership in international institutions.

Now at least one expelled Russian diplomat linked to the Federal Security Service (FSB) branch linked to attacks targeting the US energy sector has been sent to Belgrade, while another is linked to Russian counterintelligence, RFE claims after a nearly year-long investigation.