In a speech made by Dr. Zahi Hawass, Secretary General of Egypt's Supreme Council of Antiquities a few of years ago in Paris to members of UNESCO's Intergovernmental committee for the return of cultural heritage. Dr. Hawass made a fiery speech which did not help his cause and left 5 museums thinking "I lend my piece to Dr. Hawass and I will never see it again".
The biggest fight has been with the Berlin museum over a bust of Nefertiti which is the museums star. Dr. Hawass has irritated its director with repeated requests followed by Berlin's denial saying the bust is too fragile to travel.
Each of these denials has infuriated Dr. Hawass who clearly see's the bust as stolen. At this point there is a strong belief among some that Egypt's Supreme Council of Antiquities will just steal it back, if it ever gets its hands on it.
When we think Egyptology most people may think of the Rosetta stone like the Nefertiti bust, the museums star. The Rosetta stone is the British Museum's most visited object, even more so than its Elgin marbles.
As Egyptian antiquities go it is possibly the most famous object in the world and if Dr. Hawass was to get his hands on this object the President for life of Egypt would pin a medal on the doctor and the doctor would become a national hero and the stone would never see England again. Although I am sure the Cairo museum would be happy to send its copy back.
Likewise the Louvre can more than likely kiss the Dendara zodiac goodbye if they ever sent it back.
However in the last 2 cases the objects may be unique but perhaps not important enough for the Egyptian authorities to risk damaging their reputation perhaps loosing millions of dollars. I think Boston should overlook Dr. Hawass's poor diplomatic abilities and loan its bust of Ankhaf which was given through division of finds by the staff of the Cairo museum and is not seen as a stolen object.
Perhaps someday the more important of these objects will be able to be loaned back to Egypt but I don't think the director of Berlin's Neues Museum is in any rush to help the doctor get a medal pinned to his chest.