South African mountain biker Burry Stander has died in a road accident while on a training ride.
The 25-year-old, who finished fifth at the London Olympics, was killed in a collision with a taxi in Shelley Beach, the South African Sports Confederation and Olympic Committee (SASCOC) confirmed.
Stander was a two-time Olympian, having also competed in Beijing in 2008.
SASCOC president Gideon Sam said on www.sascoc.co.za: "This is indeed terrible news to start 2013 with.
"Burry was the epitome of an Olympic athlete; talented, ultra-competitive but at the same time extremely humble and a true gentleman.
Stander competed at London 2012
"SASCOC, the cycling fraternity and the entire South African sporting community mourns his passing and sends our prayers to his wife and family.
"I'm totally shattered because athletes of Burry's calibre are not easily replaced. It's an enormous loss to the entire cycling family.
"I've said this time and again but it is really time to work even harder at protecting both our runners and cyclists who used the roads daily to do their training."
Olympic and Paralympic sprinter Oscar Pistorius paid tribute to Stander.
He tweeted: "Absolutely devastated by the tragic news of Burry Stander's passing. A South African Icon and sporting great. RIP my friend."