According to the official record, only two people died when a peaceful Algerian march was brutally suppressed by Paris police on 17 October 1961. But historians and Algerian organisations say at least 200 people, maybe as many as 300, were drowned, shot or clubbed to death by police.
On the witness stand, Maurice Papon, admitted that "15 to 20" Algerian bodies were taken from the River Seine; he is the first official involved to admit such a high death-toll. But Mr Papon went on to claim the victims were "dissidents" killed by another faction of the Algerian demonstrators. The claim was greeted in France with a mixture of disbelief and anger. The interior minister, Jean-Pierre Chevenement, hinted he might allow police records to be opened in an attempt to clarify the mystery.
Mr Papon made his comments while answering questions on his conduct as a public official during the Vichy period and his high-flying career after 1945. He said the higher death tolls claimed by some for the Algerian march were "far-fetched".
Mr Papon, 87, is on trial for "complicity in crimes against humanity" for his part in the arrest and deportation of 1,500 Jews from the Bordeaux area in 1942-44. He told the court he had personally saved the lives of 139 Jews by striking them from the lists of those to be arrested. He rejected the prosecution's claim that he sought to advance his career by rounding up Jews as efficiently as possible.
He had, he said, "participated in the Nazi repression of the Jews with anguish." He had made "every effort to save as many members of the Jewish community as possible". He claimed he and his wife had "cried" at Christmas 1943, thinking of the Jews who had just departed (on his orders).
Startling as these claims were, they tended to undermine part of the case presented by Papon's own lawyers: that he was not aware that the Jews he rounded up would be sent to death camps.