PRETORIA (AFP) - South Africa's public ombudsman on Wednesday said that non-security upgrades at President Jacob Zuma's private residence which cost the taxpayer US$20 million (S$25 million) were unlawful and he must repay part of the costs.

"Some of these measures can be legitimately classified as unlawful and the acts involved constitute improper conduct and maladministration," Thuli Madonsela said in a much-awaited report released about six weeks ahead of presidential elections.