Serving as the basis for the latter charge was one brief, enigmatic document found in the British Foreign Office archive. In a ciphered dispatch dated 26 January 1944, the British minister to the Vatican, Sir Francis Godolphin d’Arcy Osborne, later the twelfth and last Duke of Leeds, reported that he had been summoned by Cardinal Secretary of State Luigi Maglione that very day. Maglione, who held doctorate, in canon low and theology, had been the papal nuncio in Switzerland and since 1939, had served as the Secretary of State. On 26 January, Maglione had sent for Osborne to say that "the Pope hoped that no Allied coloured troops, would be among the small number that might be garrisoned at Rome after the occupation."

Fonte : A Question of Race: Pope Pius XII and the "Coloured Troops" in Italy, Robert G. Weisbord & Michael W. Honhart, University of Rhode Island

Full article: http://www3.interscience.wiley.com/journal/118941395/abstract