The St. Louis Art Museum (SLAM) has sued the federal government to preclude it from initiating a forfeiture claim against the Ka-Nefer-Nefer mask. The museum was approached in January by several U.S. attorneys in January, who indicated an intention to bring a forfeiture action against the mask. Civil forfeiture was the legal mechanism under which the Portrait of Wally litigation and subsequent settlement emerged. It is a powerful tool for claimants, which uses the resources of the federal government, and a favorable burden of proof, to pursue claims for objects which may have been looted or stolen.

But in this case, rather than waiting for the forfeiture action, the museum has decided to try to preclude a suit by the U.S. attorneys, arguing that from December-January of 2005-06, the U.S. was a party to several communications regarding questions with respect to the history of the mask. They use as examples, posts and emails sent by Ton Cremers, of the Museum Security Network. He sent at least two emails to Bonnie Magness-Gardiner of the FBI, INTERPOL, as well as James McAndrew at Immigrations and Customs Enforcement (ICE). The Museum's complaint quotes emails from Cremers, which were published on the Museum Security Network:

The SLAM argues in the complaint that the relevant U.S. government officials had knowledge of the potential claim over five years ago, and the five-year statute of limitations period has expired under 19 U.S.C. § 1621. A court will decide whether these emails, and queries the Museum sent to INTERPOL in the 1990's about the mask are sufficient to have given the U.S. government actual or constructive knowledge of the potential claim. The Museum seeks a declaratory judgment under the Tariff Act that the action is barred by the statute of limitations.