The scientist who won a Nobel prize for her work in first identifying HIV says she at last believes finding a cure for the virus which causes Aids might be possible.

French virologist Francoise Barre-Sinoussi said she could not put a timescale on when it might be found but scientists were developing promising new tools.

Over 30 million people have died from HIV/AIDS since it was first identified in 1981.

Since then there has been a number of prevention and treatment breakthroughs so that people with HIV can expect to live a relatively normal lifespan - providing they have access to the correct drugs.

"The reason why we are talking about a cure today is because we have some evidence that it might be possible," Professor Barre-Sinoussi told Tim Franks on the BBC's HARDtalk programme.

Until recently medical researchers had virtually given up the pursuit of a cure but the experiences of two patients now suggest to many scientists that it may be achievable.

'Proof of concept'
One man, the so-called Berlin patient, apparently has cleared his HIV infection, albeit by arduous bone marrow transplants.

More recently, a 50-year-old man in Trenton, New Jersey, underwent a far less difficult gene therapy procedure.

While he was not cured, his body was able to briefly control the virus after he stopped taking the usual antiviral drugs, something that is highly unusual.

Professor Barre-Sinoussi said of the Berlin patient case: "It turns out today that after two bone marrow transplants we can say we cannot detect the virus anymore in his body.

"It is a proof of concept somehow that we did not have before."

There are two main approaches to finding a cure. One is to seek the complete eradication of HIV from the body. The other, a functional cure, would not eliminate the virus but would allow a person to remain healthy without antiviral drugs.

Currently a patient is required to take antiviral drugs every day. This is costly and drugs are not so readily available in poorer countries.

New tools
"The reason why we are pushing for a cure is the fact that we know it is a life-long treatment. We know that it is of course very difficult for universal access, for treatment for all.

"We know as well that there is a small proportion of patients that on long-term treatment are developing complications so that means we need to have new tools for the future," she said.

In 2008 she was awarded the Nobel Prize in Physiology or Medicine, together with her former mentor, Luc Montagnier, for their discovery of HIV.

She will shortly take up the post of President of the International Aids Society.

In her new role she will continue to be a stoic defender of funding for research which in many countries is under threat because of the economic climate.

She has in the past spoken of being "upset and furious" about cuts to international funding for tackling HIV.

While it is hoped securing funding for research will bring a cure for HIV closer, Professor Barre-Sinoussi is reluctant to commit herself as to how close we are in time to that moment that scientists have waited so long to arrive.

"I cannot answer this question if I am honest. A scientist should be honest in my opinion. We don't know."