The six postcard-sized sheets, containing threats to the Jews, were put up for sale by 79-year-old Wing Commander Ronald Mason.
The dispute involving Yahoo! in the French court comes after a highly publicised sale of notes written by Hitler for a speech to the Reichstag in 1939 highlighted the market for Nazi memorabilia.
At an auction in Swindon, Wiltsire, in March, "pointer cards" went under the hammer for £11,700.
The six postcard-sized sheets, containing threats to the Jews, were put up for sale by 79-year-old Wing Commander Ronald Mason.
As a young airman in newly captured Berlin, he traded some cigarettes for the documents.
Dominic Winter Book Auctions handled the sale of the cards, along with a catalogue of other Nazi era lots.
The surfacing of mementoes "liberated" by Allied servicemen has helped fuel a roaring trade in Nazi items.
Nazi nightie
Everything from SS Christmas cards to Eva Braun's negligée have been put up for grabs in recent years.
This booming sector of the normally sedate collecting world has prompted numerous critics, who see such transactions as at best tasteless.
In 1997, a Newcastle auctioneer swore never to deal in Nazi memorabilia again after a storm of local protest halted the sale of a drinking glass given to SS chief Heinrich Himmler by Hitler.
The Canadian War Museum expressed grave concerns about putting a Mercedes limousine owned by the Nazi leader on the market.
Curators feared the exhibit, though sure to raise millions for the museum, might act as a "powerful icon for a neo-Nazi or extreme group".
But thousands of lots are regularly auctioned through internet traders. Crockery from the Third Reich, similar to the Nazi memorabilia chillingly featured in the film American Beauty, can be had for around $45.
A spokesman from the anti-fascist magazine Searchlight says the sale of such items is "totally deplorable".
"It's objectionable that people make money from this dubious trade," he says, suggesting that if objects had real historical value they should be offered free to museums.
Private collections of such material are often a symbol of the owner's questionable ideological stance, says the spokesman.
"Some people buy this stuff out of political sympathy for the Nazis. There are a lot of people with SS daggers hanging over the mantelpiece."
Many enthusiasts say they are interested in history, not ideology. Lemmy, lead singer with heavy metal band Motorhead, says his extensive collection celebrates the Nazi taste for "elaborate regalia", not their racist beliefs.
Breaking taboos
American writer Susan Sontag maintains that Nazi memorabilia gives collectors a lurid, taboo-breaking thrill. She likens many of the books on Nazis uniforms and insignia to pornography.
Many auctioneers refuse to be drawn into the debate surrounding the legitimacy of trading in Nazi objects.
Christie's chairman Lord Hindlip has said Nazi memorabilia is "the only thing we categorically will not sell".
His company did however agree to conduct the auction of an Enigma code machine, a piece of Nazi technology which played a decisive role in the outcome of the war.
Richard Westward-Brooks, from the auction house which handled the Hitler "pointer cards" sale, speaking after the sale said historical importance was the benchmark for suitable Nazi lots.
"We don't want to get a reputation as Nazi memorabilia specialists, but if an item is of historical importance we'll treat it in the same way as the Napoleon letters we have sold."
He claimed there was nothing "weird or ghoulish" about things they sell, even the binoculars from Hitler's yacht.
"We're aware of the sensitivities. If somebody brought us Himmler's uniform or something taken from a dead prisoner at Auschwitz we wouldn't touch it," he said.
"You can't ignore history or take a moral standpoint on a particular period," he said, adding that many historically important figures had been morally abhorrent.
Mr Westward-Brooks said the Hitler speech went to a respectable document collector, not a Nazi fanatic.
He said none of those who regularly attend the sales fit the "shaven-headed, tattooed, neo-Nazi" stereotype.
"We didn't have jackboots sounding down the streets of Swindon."