Italy's foreign ministry on Monday deplored Russia's expulsion of an Italian diplomat, calling the move "unfounded and unjust" retaliation after two Russian officials were ordered to leave last month amid a spying scandal.
"We learned with profound regret of Russia's decision to expel a naval official attached to Italy's embassy in Moscow with 24 hours' warning," said a foreign ministry statement.
"We consider the decision to be unfounded and unjust because it is retaliation over a legitimate measure taken by Italian authorities in defence of national security.
Italy’s envoy to Moscow Pasquale Terracciano was summoned and handed a note saying the naval attache at the embassy, Curzio Pacifici, had been declared 'persona non grata', according to a Russian foreign ministry statement.
Rome prosecutors have launched a probe into the alleged espionage case, in which police claim to have caught an Italian navy captain selling sensitive military documents to a Russian embassy official.