British intelligence decodes in the CIA's Select Documents recorded the roundup and transfer of Italian Jews to Auschwitz.
Notes on verification
Confirmed by National Archives RG 263 description, corroborated by NARA's 2000 press release, Federation of American Scientists mirror, and a CBS News report on the same document release.
Sources
- Records of the Central Intelligence Agency (RG 263) (archives.gov)
- https://sgp.fas.org/news/2000/06/nara062600.html (sgp.fas.org)
- https://www.cbsnews.com/news/allies-knew-of-danger-to-italian-jews/ (cbsnews.com)