People who suffer from HIV disease and take antiretroviral drugs can no longer transmit the virus during sex, a new study has discovered.

Professor Alison Rodger from University College London stressed that the study provided "conclusive evidence for gay men that the risk of HIV transmission with suppressive ART (antiretroviral therapy) is zero", saying that "this powerful message can help end the HIV pandemic by preventing HIV transmission".

For his part, Dr Michael Brady, from HIV charity the Terrence Higgins Trust, said that the findings would have an "incredible impact on the lives of people living with HIV".

It was "impossible to overstate the importance of these findings", he pointed out.

"The study has given us the confidence to say, without doubt, that people living with HIV who are on effective treatment cannot pass the virus on to their sexual partners."

"We used cutting-edge technology to analyse the genetic strains of the virus in the rare cases where a new HIV infection occurred," said Professor Anna Maria Geretti from the University of Liverpool's Institute of Infection and Global Health.

"Our work was key because we were able to show that there was no relation between the virus strains of the two people in the couple,” she added.

"In other words, in all cases of new HIV infections, the new virus was so different from that of the HIV-positive partner that it must have come from somebody else."