Revealed: how Hollywood stars queued to expose 'pinkos'

If the US Congress became convinced in the late 1940s that Hollywood was a nest of communist subversives, it is not altogether surprising – many of the film industry's leading figures were willing to say it was so.

Newly released documents show that a parade of personalities from Hollywood came before the now infamous House Un-American Activities Committee to testify that the studio lots were alive with what one witness called "parlour pinkos".

Roughly 600 boxes of records from the era have been unsealed by the National Archives in Washington. They contain transcripts of testimony given during numerous investigations launched by the committee, including its probe of the alleged communist infiltration of Hollywood. The committee's work ruined the careers of hundreds of people.

"Hollywood is one of the main centers of communist activities in America due to the fact that our greatest medium for propaganda – the motion pictures – is located here," actor Adolphe Menjou declared.

"It is the desire of the masters in Moscow to use this medium for their purposes, which is the overthrow of the American government."

Among those called to testify was Lela Rogers, the mother of Ginger Rogers and an assistant to the president of RKO Pictures.

"I did grab Cary Grant one day in the commissary. I pulled him down beside me in a little booth. I said, 'Cary, be careful of this script they are going to give you. It is packed with communism, and they are going to make you say it, and I know you are not a communist'," she told the committee.

Particularly potent was the testimony of Jack Moffitt, a top screenwriter. He described being told by John Howard Lawson, the founder of the Screen Writers Guild, how he should "try to get five minutes of left-wing doctrine in every script you write".

Jack Warner, the then vice president of Warner Brothers, sought to explain the difficulties he faced in trying to excise communist references from his studio's films.

"Some of these lines have innuendoes and double meanings and things like that, and you have to take eight or 10 Harvard law courses to find out what they mean," he said.