Hugh 'Red' Radford is an agent of Interpol.
British by birth and proud of it, Radford's employment is described as "special agent attached to the British Bureau of the International Police", aka Interpol. For heroism in action, Radford had been awarded the Military Cross some time before we first meet him and when we do run across him in the first of three recorded adventures, he has been with Interpol for apparently some time. This is based on his reputation, the fact that he is known all over Europe, and because he is asked for by name.
The sobriquet he is known by, though its use is not actually employed that much, "Red", comes to him naturally and obviously by simply looking at his hair, a "fiery" red. Throw in his bright blue eyes and you have a face that attracts attention. It is described as a lean, pleasant face, normally sporting "an easy-going and slightly lazy expression, which had misled so many people".
That look of relaxed attitude can and does change when he gets into a tussle, something that happens fairly often. At such occasions, his countenance switches to steely earnestness and his smooth gliding movements turn rock solid. He is a crack shot, more than competent in a knife fight and "by any ordinary standards, Radford was a master of unarmed combat...He had never yet encountered anyone who had got the better of him in any sort of hand-to-hand encounter." The latter he proves on several occasions.
Radford is a student, apparently, of languages for he speaks several fluently, including more than a couple of Arabic dialects. He is at home in the deserts of North Africa as he is in the streets of London and he is ready to be sent wherever and whenever there is trouble brewing.