One of the three women allegedly held as a slave by a Maoist sect is the daughter of a Second World War codebreaker, it has been claimed.
Josephine Herivel, 59, is the daughter of John Herivel, one of the codebreakers who deciphered the Enigma code at Bletchley Park.
Aravindan Balakrishnan and his wife Chanda were arrested last week in Brixton on suspicion of slavery related offences.
It is thought that Ms Herivel raised the alarm after she was held against her will along with two others for more than 30 years.
Brought up in Belfast with her two sisters, she joined Balakrishnan's extremist collective in the 1970s after moving to London to study.
When her father passed away in 2011 obituaries made no mention of Josephine, only of his two other daughters.
According to family friend Frances Presley attempts to make contact were made.
She told The Times: “They have tried to contact her for years. I know she was involved in some kind of cult group. My understanding is that she cut herself off (from the family). I know they have always tried their best."
It was also revealed that Ms Herivel was prosecuted in 1978 after police raided the group’s south London headquarters.
She appeared in court alongside five fellow cult members charged with obstructing the police.
Ms Herivel was also involved with the sect when one of its members, Sian Davies died in mysterious circumstances in 1997.
Miss Davies died in hospital, seven months after falling from a bathroom window at a house in south London where the collective were living.
Documentary footage of Balakrishnan and his wife have also been uncovered by ITV News.
The pictures were shot in 1997 as part of a documentary about the death of Ms Davies.
It is thought Miss Herivel lived with the group for more than 30 years before contacting the Freedom Charity and reporting that she and two other women were being held against their will.