Russia's chief military prosecutor, Sergei Fridinsky, said a criminal case had been opened and an investigation was ongoing, adding that the smugglers included a number of businessmen.
A Navy spokesman confirmed the statement, adding that the consignment had been listed in a customs declaration as "de-commissioned, recycled ammunition."
Capt. 1st Rank Igor Dygalo said the smuggling operation was prevented by "the Navy, in conjunction with the Chief Military Prosecutor's Office and the Federal Security Service (FSB)."
According to some media reports, high-ranking Navy officials, including vice admirals and rear admirals, may have been involved in the scheme.