a fun little find from Matt Taibbi.
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He cooperated with the committee, appearing as a friendly witness, joking with panel members about wearing spurs in the service and angrily denouncing the presence of communists in Hollywood (some of whom, it must be said, were the leaders of a new screenwriters union whose picket lines Reagan had crossed).
After the HUAC hearings were over, Reagan continued his principled stand, serving as an informant for the FBI (code name: T-10) and along with his wife, Jane Wyman, providing names of suspected communists. He also tried to institute a policy in the Screen Actors' Guild of forcing members to sign loyalty oaths.But of course, you say, Reagan was not a communist. He had nothing to hide. Well, apparently he did. When he became governor in 1966, Reagan had to fill out a security clearance form to have access to the University of California's atomic research. On that form Reagan lied about having been a member of the Committee for a Democratic Far East Policy in 1946, which was later deemed subversive by HUAC. He also lied about having been on the American Veterans' Committee, which had also been deemed "communist-dominated" by the HUAC successor, the Burns committee.
more at link
http://www.buffalobeast.com/52/dyingquietly.htm