U.S. authorities have seized two paintings by Polish artist Julian Falat believed to have been looted by the Nazis during the Second World War.

The paintings, Off to the Hunt and The Hunt, were stolen during the Nazi occupation from the National Museum in Warsaw. Falat, who lived from 1853 to 1929, was a prolific impressionist painter of landscapes and frequently painted hunt scenes.

The Polish government says it located the paintings at two New York art auction houses, Christie's and Doyle New York, in 2006.

Poland appealed to the U.S. government, which led to an investigation by Immigration and Customs Enforcement of Homeland Security Investigations. After that investigation, a Manhattan court cleared the seizure of the paintings, which went ahead last Wednesday.

In its case before the court, the U.S. government argued the paintings can be seized because they constituted stolen property imported into the United States illegally.

Poland's National Museum was heavily looted during the Second World War, especially during the brutal crackdown of 1944.

Another Nazi-looted painting from Poland, Jewish Woman Selling Oranges by Aleksander Gierymski, turned up at a small auction house in Hamburg last month

With files from The Associated Press