British historian David Irving now acknowledges that Nazi gas chambers existed but admits that some of his past statements could be interpreted as denying people were gassed, his lawyer said Thursday on the eve of a court hearing.

Prosecutors this week charged Irving, 67, under an Austrian law that makes denying the Holocaust a crime. The charges stem from two speeches he gave in Austria in 1989 in which he allegedly denied the existence of the chambers. He faces up to 10 years in prison if convicted.

Irving's attorney, Elmar Kresbach, said Thursday the historian has told him he now believes that Nazi gas chambers existed.

``He changed some of the views he is so famous for,'' Kresbach told The Associated Press. ``He told me: 'Look, there was a certain period when I drew conclusions from individual sources which are maybe provocative or could be misinterpreted or could be even wrong.'''

He said additional research Irving carried out after Soviet archives were opened to scholars persuaded him that his former beliefs were ``not really worthwhile to hold up,'' Kresbach said.

Irving's new position was met with skepticism from the Simon Wiesenthal Center, which works to track down former Nazis before they die.