The government "conveyed by phone to me they will not be able to grant the visa for the reason that it would disturb relations between China and South Africa," Nangsa Choedon told AFP.
The refusal could provoke a boycott of the 14th annual peace summit, according to a spokesman for South African laureate Archbishop Desmond Tutu.
"I have heard that if the Dalai Lama is not allowed into the country, other invited guests have said they will not come," Roger Friedman said.