Russia temporarily banned imports of canned fish from Latvia and Estonia on Thursday on health grounds, prompting Latvian accusations that Moscow was trying to apply political pressure on the Baltic region.
Relations between the Baltic states of Estonia, Latvia and Lithuania have been tense since the crisis over the pro-Russian separatist conflict in Ukraine erupted last year, stirring East-West tensions unseen since the Cold War.
The crisis has made Moscow uneasy about the Baltic trio's membership of NATO and the euro zone. Latvia, Lithuania and Estonia are all former Soviet republics bordering on Russia.
Russian veterinary service authorities said the ban was due to fish products containing high levels of a toxic substance called benzopyrene.
Disputes between Russia and the Baltic states about the quality of canned fish have been going on for several years and Moscow has increased laboratory inspections of fish products and imposed import bans on individual companies.
Latvian Minister of Agriculture Janis Duklavs said Russia's decision for a wider ban might not be related to the safety of the fish.
"Perhaps I will not link the matter with Latvia's presidency of the Council of the EU, but I will remind you that Lithuanian milk producers had a similar problem when their country held the presidency [back in 2013]," Duklavs told the Latvian national news agency LETA.
In 2013, Russia suspended imports of dairy products from Lithuania, a few weeks before it hosted a summit aimed at pulling former Soviet republics like the Baltic states further from Moscow's orbit.
Latvian fish producers export around half of their catch to Russia.