SANTA ROSA (AP) — Dozens of missing paintings by a Polish artist have been found in a storage facility in Northern California.

Hanna “Kali” Weynerowska, who lived in San Francisco for 45 years, had bequeathed 78 artworks to a Polish government museum before her death in 1998. But then the paintings disappeared.

This month, FBI agents tracked down a relative who led them to the storage facility in Santa Rosa that held 75 Weynerowska originals, the San Francisco Chronicle  reported Saturday.

On Thursday, the artworks arrived at the museum in Rapperswil, Switzerland, that was established to display and preserve Polish art before the fall of the Soviet Union.

“The FBI is proud to stand shoulder-to-shoulder with our Polish counterparts in ensuring safe passage of these lost national treasures,” said David Johnson, special agent in charge of the FBI’s San Francisco office, said at a news conference Friday.

The relative handed over the paintings voluntarily and isn’t in any legal trouble, Johnson said. One or more of Weynerowska’s relatives apparently kept the works since 1998 because of the costs of shipping them and “perhaps a bit of emotional attachment.”

Caria Tomczykowska, an envoy of the Polish Consulate in Los Angeles, says the artworks’ financial value is modest — perhaps $12,000 each — but they “they are priceless emotionally ... very important to the legacy of Polish excellence.”

Born in Warsaw in 1918, Weynerowska she was a young art school graduate during World War II, when she said she joined a Polish resistance squad assigned to blow up bridges, tunnels and highways.

Weynerowska was wounded in the August 1944 Warsaw uprising against the Germans and was captured and sent to a concentration camp. She managed to escape and reached Brussels with the help of U.S. forces, said Angeline Friedman, a friend who attended Friday’s news conference.

Weynerowska and her husband, a fellow Polish refugee and resistance fighter, emigrated to Canada and then moved to San Francisco in 1953.