Around 7,370 new HIV diagnoses were made in the UK last year, according to latest figures from the Health Protection Agency.
Thirty-eight per cent of all new diagnoses were probably acquired through sex with men.
Although the numbers of gay men being diagnosed with HIV are slightly down on 2007, they are at their second highest level since recording began.
Between 1999 and 2007 there was a 110 per cent increase in diagnoses among gay men (1,450 cases to 3,050).
The survey’s authors state it is too early to say whether the annual number of new diagnoses among gay men has peaked.
Dr Barry Evans, an HIV expert at the Health Protection Agency, said: “The number of gay men diagnosed as HIV positive each year is still high and shows that a large number of individuals are still being infected.
“Gay men continue to be the group in the UK most at risk of acquiring HIV and latest national guidelines recommend that gay men should test annually.
“Safe sex is the best way to protect against HIV infection. Using a condom with all new or casual partners is the surest way to ensure you do not become infected with a serious sexually transmitted infection such as HIV.”
The research found that 57 per cent of new cases were diagnosed in heterosexuals, with 74 per cent of these acquiring the infection abroad.
Professor Maria Zambon, director of the Health Protection Agency’s Centre for Infections, highlighted the importance of early diagnoses.
She said: “Key to improving diagnosis of HIV and reducing risk of transmission is in enabling easier access to testing through different healthcare settings including general practice, and looking at innovative ways to target those communities most at risk including gay men and black African heterosexuals.
“Early diagnosis of HIV and other sexually transmitted infections has obvious advantages like access to treatment, improved survival and reduced transmission risk to partners.”
Lisa Power, head of policy at HIV charity Terrence Higgins Trust, said: “Numbers of people diagnosed with HIV are rising for many reasons. More people are getting tested, which is good. But some people don’t realise they could be at risk, and others take risks despite knowing them. HIV is not a risk worth taking.”