Two suspects in the south London slavery case ran a Communist collective in the 1970s that worshipped Chinese leader Chairman Mao Tse Tung.
The Daily Telegraph says they recruited women from other far left groups.
The newspaper claims the man and woman in their 60's set up a Communist squat in south London in 1974 and both served prison sentences associated with their political activities.
They collected and published political pamphlets calling for the downfall of Western capitalism, ran lectures, study groups and held film screenings, according to the paper.
The husband and wife were arrested last week on suspicion of holding three women against their will for more than 30 years.
The pair arrived in the United Kingdom in the 1960's and are from India and Tanzania originally.
They have been released on bail while police investigate what they say is an extremely complex investigation.