In 1943 during World War II, Veltjens also served as Göring's emissary to Benito Mussolini in Salò. He was to negotiate the distribution of the Italian National Reserves of gold bullion that had been removed from Rome to Milan by the SS. This involved its allocation as payment of Italy's debts on behalf of the various stakeholders, including the Kingdom of Italy, the new Italian Social Republic, Germany and lastly the Swiss National Bank as the major creditor. Before his subsequent flight from Milan to Rome to finalise aspects of his negotiations, Veltjens' pilot had been warned of the possibility of Allied fighters in the area, and elected to fly low across the Apennine Mountains. However, on 6 October 1943 the Junkers 52 crashed into Monte Cervellino, Veltjens and all but one of the crew died as a result.