Police are conducting house-to-house inquires in the area where three women allegedly held as slaves for at least 30 years were rescued.
A 30-year-old British woman, a 57-year-old Irish woman and a 69-year-old Malaysian woman were rescued from a house in Lambeth, south London, last month, after one of the women called a support charity asking for help.
All three women are believed to have suffered “emotional and physical abuse”, Metropolitan police commander Steve Rodhouse said.
Scotland Yard revealed today that part of the agreement when the women were removed from the address on October 25 was that police would not at that stage take any action.
A man and woman, both 67, who were arrested at the house on Thursday morning as part of the investigation, are of Indian and Tanzanian origin and came to the UK in the 1960s, police said.
They have been released on bail to a date in January.
Mr Rodhouse said two of the alleged victims met the male suspect in London through a “shared political ideology” and began living together in a “collective”.
Mr Rodhouse said the nature of the collective and how the women came to continue living at the address after it ended would form part of their investigation.
None of the women were reported missing after they were rescued, police said.
Officers have recovered a birth certificate for the 30-year-old woman, who is believed to have lived her entire life in servitude, the force added.
Mr Rodhouse said he was in a position to provide more background information to the “highly complex and difficult investigation”.
“To gain the trust and confidence of highly-traumatised victims takes time, and this must move at their pace, not anyone else’s,” he said.
“Part of the agreement on October 25 when they were removed from the suspects’ address was that police would not at that stage take any action.
“Since that date we have been working to gain their trust and evidence, that came to fruition on November 21 when we were in a position to make arrests.
“Between October 25 and November 21 none of the three victims were reported missing to the police.”
Mr Rodhouse said the suspects are of Indian and Tanzanian origin and came to the UK in the 1960s.
“We believe that two of the victims met the male suspect in London through a shared political ideology, and that they lived together at an address that you could effectively call a ’collective’,” he said.
“The people involved, the nature of that collective and how it operated is all subject to our investigation and we are slowly and painstakingly piecing together more information. I will not give any further information about it.
“Somehow that collective came to an end and how the women ended up continuing to live with the suspects.
“How this resulted in the women living in this way for over 30 years is what are seeking to establish, but we believe emotional and physical abuse has been a feature of all the victims’ lives.”
Mr Rodhouse said the 30-year-old woman’s birth certificate was the only the official documentation for her which police have recovered.
“We believe she has lived with the suspects and the other victims all her life, but of course at this early stage we are still seeking out evidence,” he added.
Mr Rodhouse said police would not release any information which would reveal the identities of the women who are described as “emotionally fragile and highly vulnerable”.
“I understand the huge public interest in this case, the desire for information and the shock that it has caused,” he said.
“However, we must take every step to protect the identities of the victims, who are understandably emotionally fragile and highly vulnerable.
“For that reason we will not provide any information that will lead to the identification of the suspects or these women that require our every effort to protect them.”
Freedom Charity founder Aneeta Prem, whose media appearances on forced marriage and dishonour violence prompted the Irish woman to contact them, said the organisation had received five times as many calls in 24 hours since the arrests.
“We have seen an extraordinary rise in calls to our helpline since the rescue of the three women came into the public domain,” she said.
“We received five times as many calls in 24 hours as we normally do in one week and are needing to increase our resources to cope with this extra demand.
“These women have had traumatic and distributing experiences, which they have revealed to us.
“What needs to happen now is that the three victims, who have begun a long process of recovery, are able to go through their rehabilitation undisturbed, without being identified.”
It emerged yesterday that the couple on bail were previously arrested in the 1970s, although police have not said why they were detained.
Meanwhile, the MP in charge of reviewing evidence of slavery in Britain said the Lambeth case was the “tip of a rather large iceberg”.