About 1,000 people in Britain have caught HIV from heterosexual intercourse with HIV-positive immigrants since Labour came to power, according to government figures to be published next week.

The spread of the infection from immigrants to the resident community has led to a fivefold increase in the number of people catching HIV through heterosexual sex in Britain since Labour was elected in 1997.

About half of those infected by HIV-positive immigrants are white Britons, while a quarter are Africans, and a quarter other ethnic minorities. The figures, which show the human cost of the imported epidemic, have prompted fears among government doctors that HIV cases which are being imported, mainly from southern Africa, could lead to a new type of HIV epidemic in Britain.

There have been several high-profile cases of HIV- positive immigrants spreading the infection within the UK.

Feston Konzani, a 28-year-old asylum-seeker, appealed yesterday against a ten-year jail sentence for knowingly infecting three women, aged 15, 26 and 27.

Britain has had a successful record of containing the transmission of HIV through heterosexual sex, with fewer than 50 cases each year until 1996. Health Protection Agency figures show that in 2003, nearly 250 people were infected with HIV from having heterosexual sex with people who caught HIV overseas, most of whom are African immigrants.

HIV doctors had previously been puzzled at why the infection was spreading so slowly among heterosexuals in Britain, remaining primarily in the homosexual community, even though in Africa it is primarily a heterosexual disease.

The government figures show that the scale of the so-called “onward transmission” has been growing rapidly.