Only four of the pepper pot aliens from the 1963 run were ever made, the other three having already been sold.
Bonhams is to auction more than 100 outfits and props from Dr Who, the first time the BBC has done so on such a scale since 1990.
Andrew Beech from the BBC said the Daleks could be dated by their different construction methods.
He said: "The original Daleks were created by a company called Surecraft Models. The 'skirt panels' had round holes in them and the hemispheres were pushed through from the back.
"With the later models, the panels were left intact and the hemispheres glued on."
He added: "I believe this is the last BBC original – the others have been sold off in previous auctions.
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