Finnish customs said Friday they had seized military materiel en route from Russia to Syria on board a Finnish ship docked at Helsinki's Vuosaari port in January.
During an inspection of the ship, customs officials discovered spare parts for tanks in a container on board the M/S Finnsun, Finnish Customs said in a statement.
According to preliminary information from the agency, the container was en route from Russia to Syria.
The customs authority's crime division has opened an investigation into the illegal export of military materiel. Four crew members have been questioned as suspects, the statement said.
M/S Finnsun is owned by Finnlines, one of the biggest shipping operators in the Baltic region, which is owned by the Grimaldi Group.
The European Union has banned all sales, delivery, transfers and exports of weapons to Syria.