Ex-Wales rugby captain Gareth Thomas is planning to team up with Prince Harry to "break the stigma" around HIV.
Forty-five-year-old Thomas announced at the weekend that he was suffering from the virus, after blackmailers threatened to expose his positive status.
In a video posted to Twitter on Saturday, he said: "I am living with HIV.
"Now you have that information that makes me extremely vulnerable, but it does not make me weak.
"Even though I have been forced to tell you this, I choose to fight, to educate and break the stigma around this subject."
Following the revelation, both Prince Harry and his brother the Duke of Cambridge were quick to share messages of support.
Celebrities, sportspeople and politicians have also sent encouragement to Mr Thomas, including Labour's Lloyd Russell-Moyle, who in November 2018 became the second-ever MP to announce he has HIV.
Mr Russell-Moyle wrote: "Extreeemly [sic] brave of you Gareth. I know it must have been hard, but you will be inundated with love and support (ignore the haters) and you will help thousands of people in the future for what you have done. Plus it will become a huge weight off your shoulders. Solidarity friend."
Now, Prince Harry - who publicly took an HIV test in 2016 - and Thomas are planning to work together to raise awareness of the condition and treatment.
The Royal has done a lot of work around HIV awareness, and launched the MenStar campaign alongside Sir Elton John, which aims to "end the AIDS epidemic by 2030".
To work with Prince Harry will be "really powerful", Thomas said.