A secret report has condemned the US government for knowingly allowing Nazis to settle in America after the Second World War.
"America, which prided itself on being a safe haven for the persecuted, became in some small measure a safe haven for persecutors as well," the 600-page document chronicling the history of the US Justice Department's Nazi-hunting unit said.
The New York Times obtained a copy of the report, which the National Security Archive, a private group, posted on its website.
Earlier, the Justice Department had declared dozens of pages from the document off-limits to the public after the archive sued to get it.
The long-secret report provided new details of many of the major cases handled by the Office of Special Investigations.
The report reflects the ways in which the US officials assigned to recruit foreign scientists after the war circumvented President Harry Truman's order not to bring in Nazi Party members or people who had actively supported Nazi militarism.
Arthur Rudolph, one of hundreds of scientists brought to the US after the war, told investigators in 1947 of attending a hanging during the war of inmates accused of sabotage at a slave labour plant manufacturing V2 rockets near Nordhausen, Germany, where he was operations director.
US immigration officials knew Rudolph had been a Nazi party member, but he was admitted to the country anyway and went on to become honoured in the US as the father of the Saturn V rocket, enabling the US to make its first manned moon landing.
Rudolph went to Germany in 1984 and forfeited his US citizenship.
The report also details a discussion at the CIA over whether former Nazi party member Otto Von Bolschwing should acknowledge his Nazi past if confronted about it when applying for US citizenship.