Clint Walters, the gay HIV activist, has died of a heart attack aged 31.

Mr Walters, who was just 17 when he was diagnosed with the disease, died at his home in Clapham, London, on Sunday.

After being diagnosed, he publicised his own story and fought to raise awareness of the disease among young people, touring schools around the country.

He also ran the London Marathon and took part in skydiving and cycling challenges to raise money.

However, he died before he was able to realise his dream of setting up the UK’s first weekend HIV testing clinic for young people under the age of 27.

Mr Walters said in 2007: “Why do I have this nagging feeling the gay scene is losing touch with what’s really important – compassion for the safety of your fellow man. Have all the 24 hour clubs, drugs and alcohol finally [taken] their toll or was it ever there in the first place?

“So, I’ve decided to turn my positive diagnosis on its head and shout it from the roof tops. If you don’t take full responsibility and call the shots, then who will?”

One of his close friends, Mark Fell, told the Independent that they would continue fundraising so “his legacy can live on”.

Mr Fell added: “He was the most amazingly inspirational person. He virtually lived on the breadline and completely dedicated his life to charity.”

Another friend, Neil Parrett told the Evening Standard that Mr Walters had been “completely selfless” about his HIV diagnosis.

“Rather than let it beat him, he focused on life and tried to make it better for other people in the same situation,” he said.

“He took calls from young people all over the country and people came to stay with him if they were struggling to come to terms with the diagnosis.”

Mr Walters was said to be in good fitness before he died.