German Chancellor Angela Merkel called on Pope Benedict XVI to make a "very clear" rejection of Holocaust denials after a former bishop was rehabilitated by the Vatican. Her demand came amid increasing outrage among Germany's Roman Catholic leaders over the pope's decision to lift the excommunication of British-born Richard Williamson, who questioned whether 6 million Jews were gassed during the Nazi Holocaust. Merkel said she "does not believe" there has been adequate clarification of the Vatican's position on the Holocaust amid the firestorm of controversy that broke out after Williamson's rehabilitation by the German-born pope. Benedict last week expressed "full and indisputable solidarity" with Jews and warned against any denial of the horror of the Holocaust, but several leading German bishops have decried the German-born pope's decision and called Williamson's rehabilitation to be revoked. "I do not believe that sufficient clarification has been made," Merkel said. Earlier Tuesday, Cardinal Karl Lehmann, the bishop of Mainz, went a step farther in an interview with broadcaster Suedwestfunk, calling for an apology from "a high level." "There must also be consequences for those who are responsible for this," Lehmann said of the decision to rehabilitate Williamson. Williamson was consecrated by the late ultraconservative Archbishop Marcel Lefebvre without papal consent. The Holy See said that removing the excommunication did not imply the Vatican shared his views. Benedict visited a synagogue during his first visit to Germany as pope in 2005 and has repeatedly made overtures to Jewish groups during other visits. But the issue is particularly sensitive in Germany, where denial of the Holocaust is a crime and Roman Catholic leaders have worked hard to restore relations with the Jewish community. As a young man in Germany, Benedict, then called Joseph Ratzinger, served briefly in the Hitler Youth corps. Williamson, in an interview broadcast late last month on Swedish state TV, said that historical evidence "is hugely against 6 million Jews having been deliberately gassed in gas chambers as a deliberate policy of Adolf Hitler." He cited what he called the estimates of the "most serious" revisionists that "between 200,000 and 300,000 perished in Nazi concentration camps, but not one of them by gassing in a gas chamber."