Norton Simon’s grandson has been removed from the foundation’s board after criticizing the museum’s handling of Nazi-looted art.

Eric Simon was voted off the board of the Norton Simon Foundation Wednesday, the Pasadena Star-News reported. Simon claims that his removal can be traced back to his critiques of how the Norton Simon Museum in the Southern California city has handled two works by Lucas Cranach the Elder that remain embroiled in a high-profile Nazi-looted art restitution lawsuit. The museum has steadfastly asserted it has legal ownership, refusing to remove the work or return it to the heir of Jacques Goudstikker, whose paintings were stolen by the Nazis. Simon has publicly voiced doubts about this position, telling the Los Angeles Times in 2014 that the museum should find an equitable solution and simply replace the paintings.

Members of the board didn’t respond to requests for comment from the Pasadena Star-News, though the publication did say Simon has faced a “number of accusations about his behavior” and did not attend the board’s meetings in 2015 and 2016. The Norton Simon Foundation, which was established by the Simon family in 1952, provides financial support to the  museum, and owns some of the work on view—but not the disputed Cranach paintings, according to the foundation's website.