The story of the mask called Ka-nefer-nefer in the St. Louis Art Museum appears to be turning on St. Louis in favour of Cairo as the mask clearly is the same mask excavated and shown in excavation photo's of the early 1950's.
Lawyers for the museum are trying anything they can to of course resolve the situation best for the museum but unfortunately the argument of statutes of limitations admits the masks correct provenance but rewards it to the museum anyway because it took too long to discover the crime.
Not likely to happen with the American authorities now involved and The St. Louis Art Museum should expect a visit in the future to hand over the mask. St. Louis' lawyers might spend their time better by suing the art dealer they bought the mask from.
The issue at present appears to be based on what kind of "contraband" the mask is, and what laws apply? St Louis' position gets weaker and weaker. The St. Louis Art museum admits the masks provenance, please go to their site to see the masks provenance according to St. Louis' acquisition.
Here is the background information on the mask: The Battle for Ka-nefer-nefer
Source of update: Looting Matters