The Conservative peer Lord Ashcroft, who owns the world”s largest private collection of Victoria Crosses, bought the medal that was given to Wing Commander Leonard Harrison,
Wg Cmdr Harrison was the pioneer of bomb disposal and his findings from pre-war experiments with fuses formed the basis for a manual followed by colleagues during the Blitz.
He is also believed to be Britain”s first winner of the George Cross – the highest gallantry award for civilians.
He died in 1989 aged 83 and his George Cross was left to his widow Hilary.
After her death last November she left it to the couple”s two children with instructions they be sold off so they would benefit from the proceeds.
The decoration was keenly fought over by bidders when it came up for auction in London.
It sold for a hammer price of £120,000 but with all the fees added on the total price paid by Lord Ashcoft was £144,000.
The medal will form part of the Lord Ashcroft exhibit of military gallantry medals at the Imperial War Museum in London.
The price achieved is second only to the world record price for a George Cross which is the £260,000 posthumously awarded to the British heroine Violette Szabo who worked for the Special Operations Executive in Nazi-occupied France in the war.
A spokesman for auctioneers Dix Noonan and Webb said: “We are delighted with the outcome of the sale, it is a tremendous price.
“The sale will directly benefit Wing Commander Harrison”s family and his George Cross will go on display at the Imperial War Museum.”
The honour was created in September 1940 but Wg Cmdr Harrison”s was backdated to February that year after he made safe a 250kg UXD that had wedged between decks of the grain carrying ship SS Kildare that had limped into Immingham Dock, Lincs.
The following month Harrison faced his most hazardous task of the war when he was summoned from gardening at home to Grimsby where a trawler had a live mine lodged in its bows.
The device, which had an external arming mechanism set to “feuer” – fire, was one not seen by the brave civilian before and he spent four hours using tools scrounged from the trawler to get at the fuse and make the charge safe.
He repeated the technique for unarming an identical mine in June 1940.
Harrison was promoted from his civilian role as a senior armament instructor to the bomb disposal school of the RAF.
Between 1941 and 1945 he made safe hundreds if not thousands of live devices all over the country.
In between, Harrison was part of a committee that came up with an ingenious plot to short-circuit the fuses of unexploded German bombs that had landed on British soil and have them smuggled into enemy munitions stores.
The idea was that the German bombers would blow up with the bombs once they had been fused.
Although the Germans discovered the scheme, it still threw the enemy into a state of panic and led them to scrap thousands of suspicious fuses.
Even after the war finished Harrison”s fearless work was not done. He went to Belgium and Germany where he defused 700 tons of bombs that had been booby-trapped.