A Russian cargo ship that sank in the Mediterranean Sea between Spain and Algeria in December 2024 following explosions in its engine room was carrying components for two submarine nuclear reactors likely destined for North Korea, an investigation has revealed.

The Ursa Major sank on 23 December with 16 crew members on board. Fourteen were rescued and brought to Spain, while two crew members — second engineer Nikitin and engineer Yakovlev — remain missing and are presumed dead.

Spanish investigators now believe the vessel may have been deliberately sunk by a Western military using a rare supercavitating torpedo to prevent Russia from delivering advanced nuclear technology to North Korea, according to details of the Spanish probe obtained by CNN.

The Russian Foreign Ministry initially said the vessel sank after an "explosion in the engine room" but provided no explanation for the blast.

However, the ship's Russian captain later told investigators that items declared on the ship's manifest as "non-dangerous merchandise" — two large hatch covers — were actually components for two nuclear reactors similar to those used in submarines.