An Estonian consul in Moscow was permitted to meet held Estonian security employee Eston Kohver at the Lefortovo prison on Wednesday.
The consul brought Kohver food, clothes and messages from relatives.
The consul told Kohver that Estonia is actively fighting for his release, the Estonian Ministry of Foreign Affairs said.
According to an agreement between Estonia and Russia, representatives are allowed to meet the imprisoned citizen of the other nation once every two months, but additional meetings can be permitted.
Kohver, who is being held by Russian authorities since September 5, has so met a consul once before, also meeting with two high-profile lawyers hired by Estonia, who he later turned down.