A pair of 16th-century wood panels that survived Bolsheviks and Nazis has become the center of a legal dispute between the Norton Simon Museum in Pasadena, Calif., where they have hung for 30 years, and an heir to a Jewish Dutch art collector who once owned them.

In separate complaints filed yesterday in U.S. District Court in Los Angeles, the Norton Simon Art Foundation and the heir, Marei von Saher of Greenwich, Conn., each asked to be declared the rightful owner of “Adam” and “Eve.” The pair of life-size oil paintings, each about 75 by 28 inches, were painted by the German master Lucas Cranach the Elder.

The Norton Simon Museum bought “Eve” in 1970 and “Adam” in 1971, for a total of $800,000, from an ancestor of the Stroganoffs, a wealthy Russian family that amassed an extensive art collection of European masters over centuries. Adam and Eve are depicted standing nude in the Garden of Eden, barely covered by the leaves of apples each holds. Adam scratches his head; Eve is menaced by a snake over her right shoulder.

The value of the panels today is not known but is almost certainly millions of dollars. A smaller single work, “Venus and Cupid,” attributed to Lucas Cranach the Elder and Workshop, fetched $824,000 at a Christie’s auction on April 19. The Pasadena paintings are a matched pair by the German master’s hand and are highlights of the museum’s collection.

The crux of the dispute lies in the whereabouts of the panels in the 1920s: whether they were part of the Stroganoff family collection when they turned up in the Church of the Holy Trinity in Kiev, as the museum foundation claims, or they found their way into the church from another source before they were sent to a state-owned museum in Kiev, as Ms. von Saher asserts.

“Our position is the Stroganoffs never owned these panels,” said Lawrence Kaye, a New York-based lawyer who represents Ms. von Saher. “There is no evidence to support any contention that the Stroganoffs ever owned them.”

Julie Cantor, a Los Angeles lawyer for the foundation, declined to comment, referring to the legal argument in its lawsuit. The foundation asserts that the Stroganoff ownership was established when the Dutch government affirmed a restitution claim by George Stroganoff-Scherbatoff, the sole heir to the Stroganoff family, in the late 1960s.

The history of “Adam” and “Eve” embodies much of the turmoil of early 20th-century Europe.

The foundation claims that the Stroganoffs lost the panels during the Russian Revolution as the Bolsheviks seized their property and art. From that time on, both sides generally agree on what happened next: In need of hard currency, the Russian government began selling works of art through auctions in Western Europe, and the panels were included in a 1931 sale in Berlin.