The campaign also targets married men who engage in gay sex
A charity has urged black and Asian men in east London who have gay sex to be tested for HIV.
Tower Hamlets-based Positive East has launched a confidential text service to raise awareness of the issue.
The campaign targets all men including married men who have sex with men and those who do not classify themselves as gay or bisexual.
The charity said 31% of men engaging in gay sex, who have an HIV infection remain undiagnosed.
The campaign, called It's better to know your HIV Status, is funded by Tower Hamlets and Newham Primary Care trusts.
Fazal Mahmood, Gay Men's Worker, from Positive East said there was a need for anonymity because of the stigma attached and "issues of sexuality are not always acknowledged or discussed".
The charity said it had also come across married men who do not describe themselves as either gay or bisexual, but have sex with men.
Mr Mahmood said: "We are seeing an increasing amount of married men who are engaging in gay sex.
"But they don't say that they are gay men as they have emotional ties with women, they go back home to their wives."
Men can text 'TestMe', 'TestTH' or 'TestNew' to 80010 MSM for more information on where to get tested.