There is also a FBI national security archived file on Anthony Blunt. It's older though. Sir Anthony Frederick Blunt (1907-1983) was a member of the Cambridge Five, a group of Soviet Union spies that operated at the highest levels of British politics and society. FBIhttps://archive.org/details/AnthonyBlunt/page/n35/mode/2up

There is also a FBI national security archived file on Anthony Blunt. It's older though FBIhttps://archive.org/details/AnthonyBlunt/page/n35/mode/2up