When most families decide to renovate their homes, most don’t expect to find much hidden behind their walls. But for one couple in Hungary, a home project has led to the discovery of more than 6,000 Nazi Holocaust documents until now thought to have been destroyed in World War II, the Telegraph reported.

The pages were found in August by a worker who had put a screwdriver through a crack in an apartment wall. Brigitte Berdefy, who co-owns the apartment, thought they had ruined a neighbor's wallpaper until her husband, Gabor, looked into the crack and saw handwriting.

About 6,300 documents were pulled from a wall cavity, all from a 1944 census, which the Nazis used to identify houses in which Jews could be held before they were moved to a ghetto in another area of Budapest. The papers were relatively intact and still readable because they were stuck in a cavity with little air. The fact the papers are intact make them a rare find for scholars.

"Most wartime papers are more faded or rotten than medieval documents, on bad-quality paper due to the rationing," Istvan Kenyeres, head of the Budapest City Archives, which has the papers now, told the Telegraph. "The content and scale of the finding is unprecedented."

Two months prior to the census, the Nazis moved into Hungary. Some 600,000 Hungarian Jews are estimated to have died in the Holocaust.

Since the Germans surrendered to the Allies 70 years ago, Nazi documents thought to have been lost have been discovered. Two years ago, the U.S. found 400 pages from the diary of Adolf Hitler confidant Alfred Rosenberg, who played a central role in the Holocaust, Reuters reported.

In September, two men claimed to have found an armored Nazi train that has been lost since World War II, CNBC reported. The train was thought to have military equipment and jewelry, as well as Nazi archive documents in it.