Gugu and his wife were part of a group attempting to summit Mount Kilimanjaro to raise money for Caring4Girls as a tribue to struggle hero Nelson Mandela.
"It is with a heavy heart that we announce that one of the climbers on the Trek4Mandela, Gugu Zulu lost his life while summiting Kilimanjaro early this morning before summiting," the Nelson Mandela Foundation said in a statement.
"Details are sketchy. What we do know is that Gugu experienced problems breathing. The medical team supporting the trek put him on a drip and they descended the mountain with him. We are informed that the medical teams tried everything possible to save his life."
The group were due to summit Mount Kilimanjaro on Monday, just in time for #MandelaDay.
Gugu posted several images on social media during the trip, including a chilling Instagram post on day two.
"Made it through day 2. My wife is doing fabulous, she has even learnt the local language. Am having flu like symptoms and struggling with the mountain but taking it step by step!! Today we managed to see our destination and our camp is literary above the clouds!! Bring day 3!!" he posted on Instagram.
Sports Minister Fikile Mbalula joined scores of South Africans in sending their condolensces.
Tragic news of the passing of Gugu Zulu announced by @NelsonMandela Foundation, Condolences to his family & friends pic.twitter.com/LqXEUHLKOv— RSA Min of Sport (@MbalulaFikile) July 18, 2016
Gugu's last days were captured on his Instagram account.
Our deepest condolences to the Zulu family and close friends.