Austrian auction house Im Kinsky may have miscalculated when it listed a long-lost Gustav Klimt portrait, only for the bid to fall through after a $37.5 million sale. Patricia J. Leahy, claiming to be Adolf Lieser’s sole great-grandchild, has filed suit in New York demanding restitution of ‘Portrait of Fräulein Margarethe Lieser.’

The auction house initially claimed the painting was possibly not of Margarethe but of a cousin and that it had changed hands after 1938. However, Leahy’s lawyers say this claim is false and that her family never knowingly parted with the artwork.

With Klimt’s other works fetching record prices in recent years, it seems the market for his art remains strong. Im Kinsky didn’t respond to requests for comment on its handling of the case, but Leahy’s lawyers believe they have strong grounds for claim.

The legal battle highlights the enduring and complex issues surrounding Nazi-looted art as heirs seek to reclaim their family treasures. As auctions continue to break records, this case might just become a landmark in the restitution fight.