The Home Office is offering to provide safe houses for women, many of them illegal immigrants, who have escaped or been rescued from British brothels run by organised crime gangs.
By Dominic Bailey
BBC News Online
Smuggling people into the UK to work in the sex industry is a complex crime, often protected by fear.
Many women who have been brought into the country under false pretences and find themselves transformed into sex slaves are too scared to leave the people controlling them.
Women who have travelled to Britain intending to work in the industry can often find themselves in a similar position.
Most women working in London brothels are from abroad
The problem for the authorities is breaking the network of organised criminals behind the traffic of young women and girls.
Police are hoping the government's new initiative - offering support, counselling and accommodation to women trying to escape the trade - could be a step forward.
At present if the women arrested during raids on brothels are found to be illegal immigrants they can either apply for asylum or be deported within 24 hours.
Most are so terrified by their ordeal they prefer to be sent home without talking to the police.
Katarina was brought to Britain from Romania and kept prisoner for several months by a man who threatened to sell her into prostitution if he disobeyed her.
"He told me he would sell me to Russian people," she told the BBC.
"He told me if I tried to run or do something he will shoot me in the head, he will cut my leg he will kill my parents in Romanian, he will kidnap my sister," said Katarina.
They are asked to service tens of customers a day, conducting quite diverse sexual acts and putting themselves and others at health risk
Chief Inspector Simon Humphrey
She managed to escape and is being housed by a housing association while she appeals her asylum claim.
The new Home Office scheme gives the women a breathing space before they have to decided whether or not to help the police.
Chief Superintendent Simon Humphrey, of the Metropolitan Police's Clubs and Vice unit, hopes the additional care will prompt some women to give information about the trafficking networks.
He told BBC News Online: "We deal with the people who control the girls in this country.
"But they will not be the people who have got them here in the first place."
Around 80% of women working in brothels - often masquerading as massage parlours, saunas and escort agencies - are from abroad.
Mr Humphrey said he did not imagine "an influx" of women willing to give enough information that would lead to prosecutions.
He said many would be too scared.
Others had not been coerced into coming to Britain in the first place and more than 80% knew what profession they were getting into, he said.
Hopefully it will allow women to make considered choices and give them all the information
Mr Humphrey said the women were often forced to work in squalid conditions.
"They are asked to service tens of customers a day, conducting quite diverse sexual acts and putting themselves and others at health risk," he said.
Mr Humphrey said any opportunity that enables a women to decide to escape that lifestyle should be applauded.
Denise Marshall, director of the Eaves Housing organisation which will accommodate and work with the women, said deportation within 24 hours had not been very successful.
Some women had been trafficked back to Europe or the UK within days, she told BBC News Online.
The new project will ensure that women who do want to return home are put in touch with local non-governmental organisations.
"Hopefully it will allow women to make considered choices and give them all the information," she said.
Carron Somerset, of the campaigning organisation Ecpat (End Child Prostitution, Child Pornography and the Trafficking of Children for Sexual Purposes), welcomed the initiative.
She told BBC News Online: "It will be a huge step forward and hopefully will help traffickers be brought to court.
"In Europe, where they use safe houses, it is proven to increase prosecution rates."
Last year an Albanian "sex slaver" who smuggled a teenager into Britain, raped her and forced her to be a prostitute for up to 20 hours a day was jailed for 10 years.
Asylum seeker Mustapha Kadiu's 15-year-old Romanian victim, who had been passed from pimp to pimp across Europe, came to London thinking she was to start a new life free from selling her body.
Other children taken in by social services have revealed how they knew they were being sent to Africa as sex slaves.
Children found in the sex industry will not be affected by the new scheme - they will continue to be referred to social services.