A few months earlier, 118 such early medieval coins were discovered at the same site.
The first traces of the treasure were found in a field near the Polish village last November by metal detector enthusiasts.
But the location was kept secret until experts from the nearby History Museum of Ostróda investigated the remarkable find.
In March, a team of archeologists led by Łukasz Szczepański returned to the site to launch official excavations.
Experts have attributed both finds to the reign of two Carolingian emperors over what is today much of France, Germany and Italy. The two emperors were Louis the Pious, who ruled from 814 to 840 AD, and his successor Charles the Bald, who ruled until 877 AD.
Szczepański told state news agency PAP that the total of 131 Carolingian coins marked the largest such find ever made in Poland.
The region where the trove was found is a former Slavic-Prussian borderland where Arabian silver dirhams were predominant in the 9th century.
The find is quite uncommon in a country well beyond the borders of the former Frankish empire, according to numismatic experts.
In previous years, three single Carolingian coins were found in Janów Pomorski, at an archeological dig exploring Truso, a legendary Viking trading post in northern Poland.
Archeologists believe the Carolingian coins discovered near Biskupiec Pomorski might have been on their way to that Viking emporium.
The trove has been handed over to the museum in Ostróda and is also being analysed by the Polish Academy of Sciences to answer questions about its provenance.
(mrs/gs)
Source: PAP