Latvia had earlier refused to disclose the official's name so as not to put any obstacles in the way of his departure from the country, a spokesman for the Latvian Constitution Protection Service said.
The Latvian Foreign Ministry said on Monday that Rogozhkin's activities were "incompatible with the status of a diplomat," and that the official should be declared a persona non grata in line with the 1961 Vienna Convention on Diplomatic Relations. The diplomat left the Baltic state on Wednesday.
Russia's Foreign Ministry dismissed the move as "unfriendly," warning that Russia could take retaliatory measures.
Latvia had made the decision to expel the Russian official based on information obtained from its security services.
Earlier on Thursday, the Russian ambassador to Latvia, Viktor Kalyuzhny, told Latvia's LNT television station that the Russian embassy had not yet received any comments from Latvia on the expulsion.
"I have a feeling that the reasons for the diplomat's expulsion are different from those announced earlier. In Latvia, which considers itself as an open and democratic country, there are too many secrets," Kalyuzhny said.
The ambassador also expressed his hope that the event would not affect relations between Latvia and Russia.
Latvian media earlier said that the official expelled from the country was Anatoly Kogalov, the first secretary of the Russian embassy in Riga. The Latvian Foreign Ministry denied the reports.
Latvia first expelled a Russian diplomat in 2004, when Pyotr Urzhumov was accused of spying. Russia expelled Juris Poikans, first secretary of the Latvian embassy, in response.
