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Jeff Bezos Billionaire Bunker's Former Owner Suing Realtor ... You Never Told Me Bezos Was the Buyer!

The guy who sold a $79 million Miami Beach "billionaire bunker" estate to Jeff Bezos is suing the realtor who handled the deal ... claiming he lost up to $6 million on the sale price, because the realtor concealed the buyer was in fact the Amazon founder.

TMZ got the docs -- an entity controlled by Leo Kryss, co-founder of Brazilian toy and electronics company Tectoy, is suing real estate firm Douglas Elliman ... claiming its CEO, Jay Parker, personally called to assure him Bezos was not the buyer behind an offer on his fancy Florida estate.

Kryss claims in the lawsuit he agreed to cut his asking price from $85 million down to $79 million after Parker assured him Bezos wasn't behind the deal -- and the purchaser wouldn't budge on the offer. But Kryss says he found out later the buyer of his Indian Creek oasis was indeed Bezos.

He sought out the purchaser's identity after learning Bezos had acquired the neighboring home for $68 million ... and he clearly thinks Bezos would likely have paid the extra $6 million Kryss was asking, so he could combine the two estates.

In essence, Kryss is claiming if he had known Jeff Bezos was the buyer, he would not have agreed to the price drop.

He's claiming Douglas Elliman misled him in order to close the deal and collect a $3.16 million commission ... and now he wants damages.

Kryss put down $28 million to buy the place back in 2014. The property is located on a barrier island in Biscayne Bay that's filled to the brim with billionaires.

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