The Oscar Chinn Case (Britain v. Belgium).
63 was a case of the Permanent Court of International Justice.
[1] The Belgian government granted significant subsidies to a Belgian company, UNATRA, that offered transportation services in the Belgian Congo.
Mr. Chinn, a British subject who operated a fluvial transport company on the Congo River could not compete (during the Great Depression) with the subsidised UNATRA's nominal prices and Britain brought a claim against the Belgian government as a matter of diplomatic protection.
[2][3] The Court decided, based on the Convention of Saint-Germain 1919 and general principles of international law, that the Belgian Government did not violate any international legal obligations to the United Kingdom.