"Four more bodies were found inside the Rocknes during searches today," Bergen police spokesman Tryggve Hillestad said in a statement.
The discovery brings to seven the number of dead sailors found inside the ship since Monday when divers began inspecting the wreck, which is docked — still overturned — at a maintenance shipyard.
The Norwegian-registered Rocknes was carrying a load of rubble to Germany when it capsized in minutes in a narrow passage of the Raune fjord. Reports indicated that it hit an underwater reef and took on water before overturning.
The accident claimed the lives of 16 Filipinos, one German and the Norwegian captain of the ship.
The seven bodies recovered since Monday have been identified only as six Filipinos and a German, Hillestad said.
Twelve people were rescued in the hours after the accident.
"In addition to searching for the dead, the divers have been asked to remain attentive to any technical clues that could be of importance to the police investigation" into the cause of the accident, he said.
Divers are to continue their search on Friday for the six bodies still missing.