South Africa refused to give the Dalai Lama a visa to visit for Desmond Tutu's birthday because the foreign ministry feared his trip would jeopardise trade ties with China, a newspaper reported Sunday.

"The People's Republic of China is South Africa's largest trading partner and was key in avoiding the last recession, among others," read a secret foreign ministry document, which the weekly City Press said it had obtained.

The document said that South Africa's "strategic relationship" with China depended on Pretoria unconditionally supporting Beijing's "one China" policy, which rejects Tibetan independence.

China regards the Dalai Lama as a "splittist" and frowns on overseas travel by the exiled Tibetan spiritual leader.

"The issue of Tibet is high in China's priority and is seen as posing a threat to sovereignty. South Africa respects the quest for China to protect its sovereignty," the document said, according to the paper.

"In dealing with the Dalai Lama, the government is sensitive to the need to uphold the right of association espoused in our constitution but must balance that with the real or imagined role of Dalai Lama," it reportedly said.

"The government, in pursuit of South Africa's national interest, has sought to balance these two issues," it said.

South Africa never publicly announced if it would grant a visa to the Dalai Lama, who was scheduled to give a speech in Cape Town on Saturday to mark Tutu's 80th birthday.

The Dalai Lama cancelled trip, saying he had received no news about his visa, provoking a furious reply from Tutu who called President Jacob Zuma's administration "worse than the apartheid government" for bowing to China and ignoring the values of the liberation movement.

South African media also reported Sunday that in the midst of the visa scandal last week, a top-level delegation from the governing African National Congress -- led by the party's secretary general Gwede Mantashe -- quietly flew off to China.

"It is about understanding the political system and how to take lessons from the Chinese on governance issues," one party official told City Press.