Three woman who worked as slaves in a south London home for 30 years were said to have been brainwashed and held by "invisible handcuffs."

The 69-year-old woman from Malaysia, 57-year-old from Ireland and 30-year-old British woman were allegedly beaten by the couple whose identities are being withheld.

The latter woman was likely born in capitivity, authorities say. All three were described as deeply "traumatized" after their rescue last month.

"What we have uncovered so far is a complicated and disturbing picture of emotional control over many years,” police commander, Steve Rodhouse, told reporters.

“Brainwashing would be a simple term, but I think that belittles the years of emotional abuse these victims have had to endure.”

Police said that it was the worst case of modern-day slavery ever uncovered in the United Kingdom.

The two suspects, both 67, were released on bail Thursday evening. Their identities are being closely guarded by authorities.

The two were forced to surrender their passports as a part of their bail terms.

The pair were arrested this week on suspicion that they were involved in forced labor and domestic servitude.

Their arrest followed a police investigation, which began after the Irish woman called a charity for help.

The charity contacted police, which removed the three women from the home and have been using trauma interrogators to question them about their ordeal.

“To all intents and purposes, to the outside world this may have appeared to be a normal family,” said Rodhouse.

The New York Times reported that one of the women may have had a forced marriage to a man that lives in the house.