1933 'PLEASE RETURN THR COVER OF THIS LETTER FOR THE PURPOSE OF AN OFFICIAL ENQUIRY' LABEL. Envelope Uruguay to London, stamp removed during transit ? and in London label affixed at upper left label 'Please return the cover of this letter for the purpose of an Official inquiry...' with '5D' charge mark, postage due no longer present. Enquiry into removal of Uruguayan stamp? (Ref 93971).