Estonia said Tuesday that it had expelled a diplomat from the Russian embassy in Tallinn, accusing the diplomatic mission of interfering in its internal affairs.

A NATO and EU member, the Baltic state has seen its ties with Russia rapidly deteriorate since Moscow invaded Ukraine, with the authorities in Tallinn staunchly supporting the war-torn country.

On Tuesday, the Estonian foreign ministry declared a member of the Russian embassy staff persona non grata, ordering the person to leave the country.

"The Russian embassy has interfered in the internal matters of Estonia in an unacceptable way," Estonian Foreign Minister Margus Tsahkna said in a statement.

Tsahkna said Russia interfered "in the judicial process, acquiring documents from a criminal case and contributing to their publication on Russian social media".

The ministry did not provide details of the case but urged an end to "the coordinated hybrid attacks of Russia's special services against the security of the Republic of Estonia".

The ministry added that it had summoned the Russian charge d'affaires to formally present a diplomatic note on the expulsion.

Last year, Estonia and Russia downgraded their mutual diplomatic relations and ordered their ambassadors to leave their respective embassies.

"After the expulsion there will be six diplomats left at the Russian embassy in Tallinn," Estonian foreign ministry spokesperson Brita Kikas told AFP.