Sputnik Estonia staffers have been forced to terminate contracts with the outlet starting January 1 after receiving threats of jail terms of up to five years from Estonian police.
Estonian authorities cite 2014 EU sanctions as a pretext for legal action against the news outlet. However, the Rossiya Segodnya Information Agency, Sputnik's Moscow-based parent company, has insisted that is not mentioned in any EU sanctions lists.
Greminger said he was aware of the situation, had received the letter and responded to it on December 31.
Additionally, he said that OSCE Representative on Media Freedom Harlem Desir was closely following the situation and was in contact with Estonian authorities on the matter.