Hudson, a mining engineer, was a rugby player, swimmer, rider, skier, boxer, and wrestler. He attended St. Andrew's College in Grahamstown, South Africa. He spoke six foreign languages and had a reputation as a ladies' man. When Winston Churchill created the Special Operations Executive (SOE), Hudson was recruited to sabotage German ships in Split harbour using limpet mines. He was commissioned on the British Army General List in 1941.
His next mission was to fight alongside the Chetniks, a royalist guerrilla force, antagonistic to both the Nazi German invaders and to the Communist partisans. He was caught twice, but escaped on both occasions.
One of Hudson's tasks was to distribute British funds in order to pay for anti-Nazi fighters. He was given more than £80,000 in sovereigns and diamonds, worth over £1.75m in today's currency, which he partially buried in peasant villages. He later confessed that after the war, parts of the treasure were buried, with the aim of retrieving it on his own account when the war ended.
Afterwards, while he was working for the army in Romania, documents show that Hudson recruited Stephen Zollner, a Hungarian Jew buying timber for the British government around eastern Europe, to retrieve the treasure. Zollner managed to acquire three parts of the buried treasure, and sent them to Hudson in a diplomatic bag. The Yugoslav authorities caught him, however, and Zollner confessed everything.
He later moved to South Africa, where he died in 1995.
The swimming complex at St. Andrew's College was named in his honour when, upon his death, he left the school a considerable amount of money for new pool facilities.