South African trade unions say they are shocked at the disappearance of 24.8 billion rand ($2.75 billion) from provincial governments which a prominent research group says could pay the president's salary at current rates for 9,000 years.

The Congress of South African Trade Unions says it is "absolutely outrageous" that such an amount has gone missing in a country with such massive poverty levels.

The Institute of Race Relations says the money could have built 460,000 low-cost homes to house a quarter of the population living in shanties or 400 new schools.

The auditor general reported last week that the money had "disappeared" in "irregular, fruitless and wasteful spending." His reports annually record other billions of dollars in state funds lost in corruption by local councils and the national government.