One in six rapes in Britain were carried out by foreigners last year, police figures have revealed.
Migrant workers and illegal immigrants were responsible for up to a third of all sex attacks in some areas.
Greater London was worst affected, with foreigners charged in connection with a third of rapes.
The figures were revealed following a Freedom of Information request by the Daily Express.
High numbers of non-UK citizens charged with sex attacks were also prevalent in areas with large immigration populations, including Cambridgeshire, Merseyside, Hertfordshire, Avon and Somerset.
Conservative MP David Davies says the figures are evidence of Labour’s failure to monitor the immigration system.
He said: ‘We need to make sure that anyone who has convictions for serious offences in their own country is not allowed into Britain.
‘Anyone found guilty of this heinous crime should be given a long prison sentence and then be deported to their country of origin, whatever that country’s human rights record.’
Sir Andrew Green, of MigrationWatch UK, said: ‘This is the downside of the free movement of people.’
Latvian serial rapist Viktors Dembovskis, 42, was given three life sentences for raping and murdering 17-year-old Jeshma Raithatha as she walked home from school.
Illegal immigrant Peter Delisser, 36, was twice deported back to his home country of Jamaica, but crept back into Britain to rape and beat a teenager in Bristol.
According to Home Office statistics, more than 11,500 women and 1,000 men were raped in the UK over a 12-month period in 2007-8.
Police say it is difficult to bring foreign rapists to justice due to the large number of migrant workers and illegal immigrants in the country.
An officer said: ‘You always have the risk of flight but with an illegal immigrant it is even more difficult because there is no record of them having come into the country in the first place.’