More than 60 per cent of the orders for Harry Potter and the Half-Blood Prince came through the US-based Amazon.com. The remaining sales originated from Amazon's stores in the UK, France, Germany, Canada and Japan.
Advance sales surpassed the 1.3 million for Harry Potter and the Order of the Phoenix, published two years ago.
By pre-ordering Half-Blood Prince Potter fans could receive the book through the mail on the official release day.
However, the Real Canadian Superstore in Coquitlam has mistakenly sold 14 copies of the book already.
Raincoast Books, the Canadian distributor of the Potter series, has won a court injunction prohibiting buyers from disclosing the plot prior to the release date.
They have also been asked to return the books to the distributor, which has promised to provide a signed copy from J K Rowling after the official unveiling.
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