A HOME Office report has recommended a new crime of "sexual exploitation" in response to evidence that hundreds of foreign women have been smuggled into Britain to work as prostitutes.

As many as 1,400 women may have been brought into the country illegally, mainly from the Balkans, Thailand and Brazil, to work in flats, massage parlours and saunas.

The Home Office study, released yesterday, says the women are being ruthlessly treated by pimps and organised crime groups, and it suggests introducing laws to give such women the right to sue their exploiters.

Inspector Paul Holmes of the Metropolitan Police vice unit, who contributed to the project, said yesterday that "sex slave" trafficking was emerging across Britain.

"We are very much of the view that it is not just a Met issue," he said. "If you go anywhere where there is an off-street sex market you will find foreign women. It is not just the big cities but some of the smaller market towns that you would not expect."

The Home Office researchers identified 71 cases of trafficked prostitutes during 1998. Of these, 51 were found in London, including Albanian, Brazilian, Czech, Hungarian, Romanian, Lithuanian, Portuguese, Slovenian, Thai and Ukrainian women. Four other forces reported cases in smaller centres such as Southampton and Northampton.

 Researchers also found evidence that teenage Nigerian girls were being brought to Britain and - using the lack of immigration controls within Europe - then sent to Italy to work as prostitutes.

The report, compiled by the University of North London's child and woman abuse studies unit, estimated that the 71 known cases could represent just 5 per cent of the total. At a recent seminar organised by the Government and involving workers in health projects, it was suggested that 90 per cent of the migrant prostitutes had not been trafficked to Britain but were here of their own will.

But the University of North London team took a broad view of trafficking, which ranged from women who had been forcibly abducted to those who were aware that they were coming to Britain to work as prostitutes but did not realise the degree to which they would be exploited.

"The reality for most trafficked women is that they 'earn' considerable amounts of money, since they are expected to work longer hours, and service more clients, than indigenous prostitutes, yet they are lucky if they receive any of it," the study said.

Typically, an eastern European prostitute in Britain will have been recruited through an advertisement, with the attractive proposition of her own accommodation.

 Many expect to earn large amounts while working out a six-month visa but are invariably taken to a brothel owner and made to give up their passports.

Some have been given three months to pay off a pounds 5,000 debt to the people who have smuggled them in. After that, they have been charged exorbitant amounts for rent, laundry and other "expenses".

The Home Office report said: "Should any of the women protest at their treatment, a series of threats will be made to friends and family. Should these levels of coercion still not produce compliance, physical and sexual violence will be used."

The University of North London team is shortly to travel to the Balkans to investigate the trafficking in sex slaves in main source countries.