LONDON, AUGUST 30: Former cavalry officer James Hewitt, who had a love affair with Diana Princess of Wales, will not reveal the contents of more than 60 love letters she wrote to him in a forthcoming book, his lawyer Michael Colman said on Monday.``The letters as such are not to appear in the book. James has always made it clear that they are private,'' Colman told Sky News on Sunday night. ``He will not disclose them and he will not, for example, sell them. That has been the case since they were written to him by Diana 10 years ago,'' said Colman.The lawyer was reacting to reports in several British newspapers at the weekend which said Hewitt planned to disclose the contents of the letters. They were said to contain material which would ``a devastating effect'' on the late princess's two sons William, 17, and 14-year-old Harry.Diana died in a Paris car crash on the morning of August 31, 1997. Colman also denied Hewitt had written the book as a ``money-spinning exercise''. He refused tocomment on reports that Hewitt had sold the serialization rights to the book ``for a considerable sum'' to a national newspaper.