According to Odyssey, the bars of silver recovered so far represent only about 20 percent of all the bullion residing in the Gairsoppa.
Records suggest the Gairsoppa carried a cargo of silver worth £600,000 at the time, which would equate to approximately 7 million ounces of silver.
"One record clearly indicates that 2,817 silver bars were loaded at one port and another report lists an unconfirmed amount of silver (most likely coinage)," the company said.
"The difference between the amount paid out under the War Risk policy (£325,000) and the £600,000 sterling referenced in contemporary documents is possibly explained by additional uninsured government-owned silver aboard," Odyssey stated.
Under the agreement with the British government, Odyssey will retain 80 percent of the silver's value.
WATCH VIDEO: See how Odyssey finds and recovers sunken treasure.