JOHANNESBURG - South African former world heavyweight boxing champion Cornelius "Corrie" Sanders died on Sunday after being shot by armed robbers who burst into his nephew's 21st birthday party, the South African Broadcasting Corporation reported.

New WBO heavyweight boxing champion Cornelius "Corrie" Sanders of South Africa raises his arm in celebration as Wladimir Klitschko passes by in Hanover in this March 8, 2003, file photo. Sanders died on September 23, 2012, after being shot by armed robbers who burst into his nephew's 21st birthday party, the South African Broadcasting Corporation reported. [Photo/Agencies]

Sanders, 46, was hit in the arm and the stomach when the robbers raided a restaurant outside the town of Brits in North West Province where he and other family members were attending the party, the SABC said on its website.

He was rushed to hospital but died from his wounds in the early hours of Sunday.

"Three guys walked in and then started shooting -unfortunately Corrie Sanders was wounded in that shooting - and they stole some purses, cellphones and car keys from other people," Johan de Jager, owner of the Thatch Haven Country Lodge restaurant, told the SABC.

Sanders, nicknamed "The Sniper" because of his fierce left, won the World Boxing Organization heavyweight title in 2003 with a surprise knockout of Ukraine's Wladimir Klitschko.

Out of his 46 professional fights, he lost only four.

Tributes poured in on Sunday from admirers and fellow sports stars. "He was just a fantastic sportsman," former South African rugby captain Naas Botha told eNews Channel Africa.

Police were searching for the robbers.