Foreigners with HIV will be given drugs costing £20,000 a year on the NHS under Government proposals to prevent the spread of the disease.
The treatment will be offered to non-British residents in England, including failed asylum seekers and students on temporary visas.
It is not clear how many patients this will affect or what it could cost the health service, but ministers believe that many foreigners with HIV are not coming forward for treatment as they cannot afford to pay for it.
They claim that every HIV case properly diagnosed and treated will prevent another five people from contracting the disease.
The drugs, called anti-retrovirals, slow down the damage to the immune system, thus preventing patients from developing Aids.
They also make the virus less infectious, reducing the likelihood that it will be passed on through unprotected sex or from mother to baby during birth or breastfeeding.
The Government’s proposals will bring England into line with Scotland, Wales and every other country in the European Union where the drugs are already offered free to foreign nationals.
Foreigners are already given free NHS treatment for every other infectious disease such as hepatitis, tuberculosis and measles.
Although at present they are not entitled to the HIV drugs on the NHS, it is unlikely that hospitals or doctors would refuse to treat them.
Campaigners believe such measures should have been brought in years ago and the only reason they have been so long coming is the stigma attached to Aids.
The Government insists that it will ensure that the free drugs will not be exploited by so-called health tourists flying in to take advantage of the NHS.
Public Health Minister Anne Milton said: ‘This measure will protect the public and brings HIV treatment into line with all other infectious diseases.
Treating people with HIV means they are very unlikely to pass the infection on to others.
‘Tough guidance will ensure this measure is not abused.’
Professor Jane Anderson, chairman of the British HIV Association, said: ‘This is good news for people living in the UK who are HIV positive and also for public health in general.
‘Research shows that proper treatment reduces infectiousness and so stops other people becoming infected. It’s a decision that will certainly save lives and also improve the quality of life of many who were previously shut out from appropriate treatment.’
Yusef Azad of the National Aids Trust said: ‘If someone is tested and treated early, it is much cheaper than presenting themselves at hospital with a much more serious, complex condition that can cost tens of thousands of pounds to treat.’
The annual number of new cases of HIV has almost doubled in the last decade from 2,000 in 2001 to 3,800 in 2010, according to the Health Protection Agency.
There are no figures for the number of people with HIV who have not yet been diagnosed or what proportion are foreign nationals, but some estimates suggest that around 97,400 people in England have the virus.
A Department of Health spokesman said: ‘This is about protecting this nation’s health. It will significantly reduce the spread of HIV. It is not an invitation for people to come here for free treatment – there’s no need because in most countries access to HIV treatment has increased greatly over the last few years.
‘For every case diagnosed and treated, figures suggest that between four and five cases are likely to be prevented over a person’s lifetime. This will save the NHS between £12,000 and £20,000 a year or around £300,000 over the lifetime of each person.’
The Government is understood to have reached its decision amid concerns that the potential costs of treatment dissuade foreigners from seeking help.
Former health secretary in the Thatcher government, Lord Fowler chaired a House of Lords inquiry into the state of the HIV epidemic in Britain.
It came nearly 25 years after he launched the first major campaign warning of the dangers of Aids.