British police on Thursday rescued three women from a house in London where they are believed to have been held as slaves for at least 30 years.
Scotland Yard police headquarters said the victims were a 69-year-old Malaysian, a 57-year-old Irish woman and a 30-year-old Briton.
The women were described as "highly traumatised".
Detectives arrested a 67-year-old man and a 67-year-old woman at their home in south London.
Police swooped after being contacted last month by the Freedom Charity, which received a call from a woman stating she had been held against her will in a house in London for more than 30 years, Scotland Yard said.
Police said the woman had contacted the charity -- which helps young people to understand forced marriage and honour-based violence -- after seeing a television documentary featuring the group's work.
Aneeta Prem, the Freedom Charity's founder, said their treatment was "barbaric" and their liberation an "amazing story".
"You're basically looking at domestic slavery, and you wouldn't expect that to be happening in the UK, in London, in 2013," she told Sky News television.
Prem said she thought the women had suffered physical abuse but that they had not reported any sexual abuse. There was not thought to be anyone else in the house except the women and the couple.
She said the two people arrested were the "heads of the family" in which the three women were kept.
"The ladies were absolutely terrified of these people," she said.
"They did have rooms that they could use but they were very restricted on everything they could do.
"I don't believe the neighbours knew anything about it at all.
"I think you would describe it as just an ordinary house in an ordinary street that wouldn't raise any concerns with any neighbours or anyone else.
"I just can't believe that human beings can treat each other that way. It's something that's so barbaric and so out of everyone's imagination that anybody could treat anybody in such a way that people feel that they are slaves."
She said the women had been taken together to a place of safety, were happy and were doing well considering their ordeal.
The women will be afforded help and support.
"They're going to hopefully have happy, fulfilled lives once they get over this horrendous trauma, if they ever will get over the trauma that they've been in," said Prem.
Detective Inspector Kevin Hyland, from Scotland Yard's Human Trafficking Unit, said police inquiries established the location of the house and with the help of "sensitive negotiations" conducted by the charity, the three women were rescued.
"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," he said.
"We have launched an extensive investigation to establish the facts surrounding these very serious allegations."
Earlier this year, three women who were imprisoned in a house in Cleveland, Ohio, for more than a decade were freed.