It's been written by an anonymous Chinese author, but has JK Rowling's name on the front cover.
The Times says JK Rowling's agency is investigating the book.
A spokesman said: "We take this issue extremely seriously and are looking into the matter urgently."
Harry Potter and Leopard Walk Up to Dragon begins: "Harry doesn't know how long it will take to wash the sticky cream cake off his face."
The People's Publishing House, who own the copyright to the Chinese book, said the writer had also used a photograph of JK Rowling.
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