Charl van den Berg has died aged 33.
It is understood that he died in hospital in South Africa after losing a short battle against lymphatic cancer.
Mr Van Den Berg won the title Mr Gay South Africa in 2009, before going on to win Mr Gay World in 2010 at the Oslo finals.
He was a prominent LGBT rights activist, who was involved in Red Ribbon HIV-awareness.
In a statement announcing his death, the Mr Gay World organisation said: “Charl always conducted himself in a friendly, approachable and exemplary fashion, keeping his feet firmly on the ground and doing the job he was chosen for without airs and graces.
“His infectious laughter and warm character made him an absolute pleasure to with. We have lost a member of our family, a hero and a friend. Charl van den Berg will always be an icon to many around the world.”