Latvia has announced it is expelling a Russian diplomat, citing breaches of a decades-old security convention.
The diplomat at the Russian embassy, who has not been named, was ordered to leave on the basis of information supplied by Latvian security agencies, an official from the country's foreign ministry said.
"The Latvian foreign ministry received information today from the security services that there has been a violation of the Vienna Convention of 1961 by this diplomat and that he poses a security threat to Latvia," Ivars Lasis, a ministry spokesman, said.
Such statements are often used to describe spying or other breaches of the Vienna Convention, which governs the behaviour of diplomats.
A separate Latvian foreign ministry statement said that the individual had "performed actions that are inconsistent with the status of a diplomat".
The statement said that Viktor Kalyuzhny, Russia's ambassador to Latvia, had been called to the foreign ministry to be informed of the decision.
The expulsion comes after Latvian television station TV3 reported on December 30 that Latvia was set to order a Russian embassy first secretary to leave.
Maris Rieksins, Latvia’s foreign minister, denied on Monday that the man being expelled was the first secretary at the Russian embassy.
Latvia and Russia signed an agreement last year to formalise their border, 17 years after the Baltic state regained independence.
However, relations have deteriorated amid Russian allegations of discrimination by Latvia against its large Russian-speaking minority.
Russia has also cut off oil supplies to Latvia's western oil port and has expressed unease about Riga's membership of Nato.