The enzyme is still far from being ready to use as a cure, the authors warned, but it offers a glimmer of hope for the more than 40 million people infected worldwide.

“A customised enzyme that effectively excises integrated HIV-1 from infected cells in vitro might one day help to eradicate (the) virus from AIDS patients,” Alan Engelman, of Harvard University’s Dana-Farber Cancer Institute, wrote in an article accompanying the study.

Current treatments focus on suppressing the HIV virus to delay the onset of AIDS.

What makes HIV so deadly, however, is its ability to insert itself into the body’s cells and force those cells to produce new infection.

“Consequently, the virus becomes inextricably linked to the host, making it virtually impossible to ‘cure’ AIDS patients of their HIV-1 infection,” Engelman explained.

That could change if the enzyme developed by a group of German scientists can be made safe to use on people.

That enzyme was able to eliminate the HIV virus from infected human cells in about three months in the lab.

The researchers engineered an enzyme called Tre which removes the virus from the genome of infected cells by recognising and then recombining the structure of the virus’s DNA.

This ability to recognise HIV’s DNA might one day help overcome one of the biggest obstacles to finding a cure: the ability of the HIV virus to avoid detection by reverting to a resting state within infected cells which then cease to produce the virus for months or even years.

Researchers were also optimistic about developing additional enzymes which would target other parts of the virus’s DNA.