A pair of French Egyptologists who suspect they have found a previously unknown chamber in the Great Pyramid urged Egypt's antiquities chief to reconsider letting them test their theory by drilling new holes in the 4,600-year-old structure. Jean Yves Verd'hurt and fellow Frenchman Gilles Dormion, who has studied pyramid construction for more than 20 years, are expected to raise their views during the ninth International Congress of Egyptologists in Grenoble, France, which starts Monday. They also published a book about their theory this week. Standing in their way is Zahi Hawass, the director of Egypt's Supreme Council of Antiquities, who heatedly rejected the theories during a Cairo press conference this week. "There are 300 theories concerning hidden rooms and other things inside the pyramid, but if I let them all test their theories they will do untold damage to the pyramid, which was built with the blood of Egyptians,'' said Hawass. "I will not let Egyptian blood be damaged by amateurs.'' He said earlier requests from the same pair were turned down in 1999 and 2003.