The two Russian diplomats who were expelled by the Czech government last week left the country on Sunday, boarding an Aeroflot flight to Moscow.
The news was confirmed by Czech Foreign Minister Tomáš Petříček, who said the Russian side had rejected Czech efforts to resolve the matter in a discrete manner leaving the government no option but to declare the diplomats persona non grata, giving them 48 hours to leave the country.
Prime Minister Andrej Babiš said on Friday that the two men were involved in a bogus information plot in which the Czech counter-intelligence service BIS was fed information that a Russian agent had been sent to Prague to kill elected Prague officials with the poison ricin.
The prime minister said the incident, which resulted in a large scale investigation and severely strained bilateral relations, stemmed from a dispute between Russian embassy staffers. Such behaviour could not be tolerated, he said.
The head of Russian civil intelligence, Sergei Naryshkin, called the diplomats expulsion a "vile provocation" by the Czech authorities, saying reciprocal action would follow.