810.74/990a: Telegram
The Secretary of State to the Ambassador in Argentina (Armour)
955. Now that Argentina has forbidden transmission of diplomatic coded messages over international radio circuits, it is possible that Axis missions are using other channels, either legal or clandestine, to communicate with their respective governments by code. One such possibility might be via neutral diplomatic missions in Rio and radio station “Radiobras”, which, it is understood, still permits transmission of coded messages to neutral countries.
Will you please investigate this matter, possibly talking it over with Hayes54 and your British colleague, and report to Department any information you can obtain in this matter together with your recommendations. Included in such report, will you please let us have as detailed information as possible concerning traffic to and from neutral missions during the 2 or 3 weeks before June 16, and since June 16, in order that we may determine whether there has been any suspicious increase in such neutral traffic which would indicate that Axis missions are using such channels for the transmission of their own messages.
- George W. Hayes, Manager, Transradio Internacional↩