New York ? Four first edition copies of Harry Potter books inscribed by author J.K. Rowling to her father have been sold for nearly $90,000.

The highest bid of $48,000 at a recent auction went for the fourth book in the fantasy series, “Harry Potter and the Goblet of Fire.”

The books were among seven first edition presentation copies that the author inscribed to her father, Peter J. Rowling, who consigned them to Sotheby’s fine books and manuscripts sale. The other three copies did not sell, said Kristin Gelder, a spokeswoman for the auction house. None of the buyers was identified.

Sotheby declined to say why Rowling decided to sell the books. And there was no immediate comment from the author and no immediate response to a message left with her agent after business hours in London.

The first edition dedication copy of “Goblet of Fire,” complete with a handwritten note about the character Ron Weasley, had been estimated to sell for between $50,000 to $75,000.

(A presentation copy is a book the author has marked with an inscription and presented to someone. A dedication copy is a book in which the author has written a note to the person whose name appears on the dedication page. “Goblet of Fire” had been dedicated to the author’s father.)

A first edition presentation copy, inscribed by the author to her father and stepmother, of “Harry Potter and the Prisoner of Azkaban” — the third book in the seven-book series — sold for $19,200. Its pre-sale estimate was $20,000 to $30,000.

On the facing page of that book, Rowling has circled the numeral one, indicating a first printing, and written, with a pointing arrow, “Guard it with your lives!!!”