NAZI leaders planned to eliminate Christianity and convert followers to an Aryan religious code, according to a newly-discovered document from one of the chief investigators at the Nuremberg trials.

General William Donovan prepared the 108-page dossier after interviewing surviving Nazis and studying archives after Germany's defeat in 1945.

It had lain in a collection of notes, transcripts and photographs in the offices of his law firm in America, and came to light when another attorney bought it.

The document, now released online by the Rutgers Journal of Law and Religion, describes how the Nuremberg investigators concluded that the Nazis planned to infiltrate churches, discredit, jail and occasionally murder Christian leaders.

According to the document, Nazi leaders sought ''a complete extirpation of Christianity and the substitution of a purely racial religion tailored to fit the needs of National Socialist policy''.

It says: ''National Socialism, by its very nature, was hostile to Christianity and the Christian churches.''

While the document offers insight into how prosecutors reached their conclusions in the 1945-1949 war crimes trials, scholars said the Nazi plan was not surprising. Michael Salter, a law professor at the University of Central Lancashire, said General Donovan's complete 148-volume collection was almost like an undiscovered secret history.

''There's some material there which Donovan should basically have never taken away from the Nuremberg trials,'' he added.

The cache includes transcripts in German and English as well as background memoranda, some of which are marked top secret.

Relations between the Axis powers and Christian leaders have been the subject of some controversy. Mussolini concluded the Lateran Pacts with the Vatican in 1929, prior to Hitler's rise and the policy of genocide against the Jews in which millions were murdered.

A spokesman for the Roman Catholic Church in Scotland said: ''This evidence reinforces the idea that Christianity and Nazism were, and are, utterly incompatible. Many Christians gave their lives in opposition to Nazism and this document reminds us of the enormous sacrifices which were made.''

The transcripts are not unique, but the general supplemented his set of trial-related documents with original photos, letters, sketches, handwritten notes and additional evidence.

When he left Germany, he took the documents, had them bound in blue leather and kept them in his New York law office. The papers gathered dust for decades after his death in 1959, until another lawyer recognised their importance and handed them to Cornell University, with an agreement to publish the papers in the online law journal.

''Until now, it would have taken a lot of work to get a lot of this information,'' said Julie Seltzer Mandel, editor of the journal's Nuremberg project, whose grandmother survived the Auschwitz death camp.

''For as long as I can remember, the importance has been on remembrance and making sure the story is told accurately so history won't repeat itself,'' she said.

Pastor Martin Niemoeller was one of the prominent German Christians who resisted Hitler and later survived detention in Dachau. Another minister, Dietrich Bonhoeffer, was involved in a 1944 plot to assassinate Hitler and was later hanged.