Martin Bailey of the Art Newspaper has an article on an unpublished Dutch report by Jos van Beurden which indicates diplomatic bags are being used to smuggle antiquities. Under the 1961 Vienna Convention on Diplomatic Relations, diplomatic bags should “not be opened or detained”. The article is short of any hard numbers, and it seems the unpublished paper is only based on anecdotal evidence. However, a number of influential writers in the field, including Colin Renfrew, have indicated that diplomatic bags are a big source of the problem.
It seems we are stuck between a rock and a hard place here. On the one hand, without more data on the amount of objects being smuggled, it will be difficult to recommend a change in current practice. However, the anonymity which pervades the antiquities market seems to preclude the gathering of that data. Perhaps it will take a high-profile incident to force a change in current practice.
I am not convinced that these are a huge problem. Shouldn’t diplomats have better things to do than smuggle antiquities. In addition, without more information, this would only seem to add to the speculation.