A new study has found that closeted men who have gay sex may be underestimating the risk of catching HIV.

Researchers from the University of Edinburgh found that public health messages should be used to target men who aren’t open about having gay sex because this group has been “neglected.”

The study revealed that men who weren’t open about their sexuality – and who had sex with other closeted men – were more likely to contract HIV from each other, instead of from out gay or bisexual men.

The researchers believe these men are less likely to take on board prevention messages, decreasing their awareness of their risk of HIV.

The study involved looking at archived anonymous data to examine the ways HIV is transmitted.

Scientists looks at the genetic coding of virus samples taken from more than 60,000 HIV-positive individuals in Britain.

The researchers created networks linking the infections, in order to see how the virus was transferred from person to person.

The same group of scientists also discussed – in earlier work – that 6 percent of HIV-positive men who said they were straight when they were diagnosed had caught the virus by having sex with other men.

The new research concluded that not openly gay or bisexual men tended to have fewer sexual parters, and generally choose to have sex with one another. They said this behaviour meant some of them could be underestimating their HIV risk.

Andrew Leigh Brown of the School of Biological Sciences at the university, who led the study, told The Times: “Nondisclosed men who have sex with men are more likely to be infected by each other than by openly gay men and less likely to be aware of their risk.

“The finding shows that public health messages should be targeted specifically at this neglected group. It also shows that large-scale studies of health data can be carried out without risk to individual privacy.”

Terrence Higgins Trust recently launched a new programme to make HIV self-testing kits free to all gay and bisexual men, as well as trans women.

PinkNews tried out the  HIV self-testing kit live on Facebook with Terrence Higgins Trust’s Liam Beattie at PinkNews’ London office.

Last month, new research suggested gay and bisexual men who engage in chemsex are more likely to be newly diagnosed with HIV, hepatitis C and other sexually transmitted infections than those who do not.