The three "extremely traumatized" women rescued from alleged servitude in a London home had been held against their will for at least 30 years, police said.
The youngest, a 30-year-old British woman, is believed to have spent her entire life in servitude, police said, although it's unclear exactly where she was born.
"It appears this person had been kept in servitude, slavery or forced labor for 30 years," Det. Insp. Kevin Hyland of trafficking Scotland Yard's Human Trafficking Unit told ABC News. " From what we know at the moment, there was no real contact with the outside world.
"These circumstances, whilst extraordinary because we are talking about 30 years, we have experienced similar cases but never of this magnitude."
The police Human Trafficking Unit this morning arrested two suspects, a 67-year-old man and a 67-year-old woman, at their home in south London as part of an investigation into slavery and domestic servitude. They later were released on bail, The Associated Press reported.
The alleged captives -- a Malaysian woman, 69, an Irish woman, 57, and the British woman -- had some "limited freedom" but police say the women spent much of the past 30 years inside the house, police said.
The Irish woman called Freedom Charity on Oct. 18, saying she was being held against her will, along with two other people, police said.
The charity then notified the Metropolitan Police Service's Sexual Offences Exploitation and Child Abuse Command on the same day, and the information was passed along to the Human Trafficking Unit Oct. 21, police said.
Working with police, the charity arranged to meet the women at an agreed-upon location Oct. 25, police said.
Two of the alleged captives -- the British woman and the Irish woman -- met with charity workers and the police on that day. They identified the location where they had been held and police said they went to the address and removed the Malaysian woman.
All three were taken to a place of safety that same day.
The two arrests were made this morning, or "as soon as officers had established the facts and were satisfied the victims were aware of police intentions," police said.
"This is the very early stages of a complicated and sensitive investigation," Hyland said. "These women are highly traumatised, having been held in servitude for at least 30 years with no real exposure to the outside world, and, trying to find out exactly what has happened over three decades will understandably take some time."
None of the women are related and there is no evidence of sexual abuse, police said.
"We applaud the actions of Freedom Charity and are working in partnership to support these victims who appear to have been held for over 30 years," Hyland of the trafficking unit said.
"A television documentary on forced marriages relating to the work of Freedom Charity was the catalyst that prompted one of the victims to call for help and led to their rescue."
The woman phoned the charity last month, and "as soon as we got the information, we acted as soon as practicable, almost immediately, as quick as that could happen," Hyland told ABC News.
"It has taken us three weeks for us to establish the facts of what happened to them in order to make arrests today."
The women are getting psychological and medical assistance in an "extremely well cared for environment," he added.
The women were "basically domestic slaves," Aneeta Prem of Freedom Charity told the BBC.
Prem also told Sky News that the alleged victims were able to walk out of the house after receiving help from the charity. "We started in-depth to talks to them when they could. It had to be pre-arranged," Prem said.
"They gave us set times when they were able to speak to us. It was planned that they would be able to walk out of the property. The police were on standby."
The two suspects are considered the "heads of the family," Prem said, adding that the rescued women believed they were in "massive danger" and were "absolutely terrified."
The Freedom Charity is a UK-based organization that aims to "raise awareness and prevent child abuse, keeping children safe," according to its website.