The latest find could also reignite debates about why the Allies took no action, such as bombing, to disrupt the operation of Auschwitz.

The information was contained in a memorandum passed to the British government — and handed to U.S. President Franklin Delano Roosevelt by Jewish leaders at a White House meeting on Dec. 8, 1942.

It starts by noting that 2 million Jews had already been killed. It then states: "The five million Jews who may still be alive in Nazi-occupied territory are threatened with total extermination under the terms of an official order by Hitler calling for the complete annihilation of Jews in Europe by 31 December 1942."

It went on to inform Roosevelt that "centers have been established in various parts of Eastern Europe for the scientific and cold-blooded mass murder of Jews. Polish Christian workers, eyewitnesses, have confirmed reports that concrete buildings, on the former Russian frontiers, are used by the Germans as gas chambers in which thousands of Jews have been put to death."

The memorandum also specifically informed Roosevelt: "The slaughter of trainloads of Jewish adults and children in great crematoriums at Ozwiencim [Auschwitz] near Cracow is confirmed by eyewitnesses in reports which recently reached Jerusalem."

The document was discovered by doctoral student Barbara Rogers at the British Public Record Office while researching the British government's response to the Holocaust.

"This is the only document to prove beyond question that the British government and President Roosevelt knew the true role that Auschwitz-Birkenau played in the Final Solution at the time," she said. "The question is: Why didn't they disclose it?"

Several explanations have been offered for Britain's apparent attempt to conceal early information about Nazi atrocities against Jews:

*The British were concerned that the release of information would compromise their successful code-breaking operation, which allowed them to intercept German communications.

*They feared a flood of Jewish emigration from Europe to Palestine.

*They were anxious to avoid a popular backlash if they were perceived to be fighting a "Jewish war."