Thirteen people have been arrested over a trafficking ring which saw a pregnant woman almost tricked into an abortion following a sham marriage.
The 20-year-old from Slovakia was sold for up to £15,000 by a gang in Greater Manchester who organised a marriage to a man facing deportation, police said.
The woman told an interpreter at hospital she had been "sold against her will" and was "appalled" by the prospect of an abortion.
Ten men and three women were arrested.
The group, aged between 24 and 57, were arrested at addresses in Rochdale, Failsworth and Cheetham Hill on Wednesday and are still in custody.
Police said the woman, who was 25 weeks pregnant, was flown to Luton in May, believing she was going to visit her sister.
She was met by a man who claimed to be her sister's friend and was taken to an address in Failsworth, Oldham before being sold to another man.
In July, she was married under Sharia law in Rochdale.
The woman was later taken to hospital for an appointment by a woman who acted as an interpreter and told staff she wanted an abortion.
However, she was spoken to by an independent interpreter and police said it became clear "she was being sold into a marriage against her will".
Det Insp James Faulkner said: "She was completely unaware of this group's nefarious motives and by the time she realised what was going on, it was too late.
"She was met by a male unknown to her and trafficked to an address in London and then further on to the north west where the initial pretence of her coming to visit family was quickly dismissed and she was sold to an unknown male."
He said she was sold to a male and "lived with him for the purpose of securing his immigration status in this country".
Det Insp Faulkner said there was a trend for trafficking pregnant women as they are deemed more attractive for obtaining immigration status.
Police said they believed there were currently 400 cases of sham marriages in Manchester.
"Home Office statistics place a cost of £40,000 on the UK economy for each sham marriage," Mr Faulkner said.
Those arrested were held on suspicion of offences including trafficking people for exploitation and conspiracy to facilitate breach of immigration law.