Doctors in Berlin, Germany have accidentally stumbled across a possible cure for HIV, or at the very least a new direction in the treatment of the condition.

Two years ago a 42 year old American man living in Berlin was facing certain death – he was suffering from both leukaemia and AIDS. He had to undergo a bone marrow transplant to treat the leukemia, and while this was happening he had to stop his AIDS medication.

The cancerous cells were replaced with healthy stem cells from a donor who had a genetic mutuation known as CCR5, which basically means that they have a natural genetic resistance to HIV. 20 months later the patient is not only leukemia free, but he’s also HIV free too.

Dr Gero Hutter from Berlin’s Charite Hospital has told media that “the procedure comes with such a high mortality rate that it would be ethically unjustifiable except for this specific situation when a patient was forced to have a transplant because of another disease.”

However, other experts say that this does raise new hopes that gene-therapy may someday cure the virus.