The complete series of South African bank notes will bear Nelson Mandela's image, the country's president said on the 22nd anniversary of the anti-apartheid leader's release from prison.

"With this humble gesture, we are expressing our deep gratitude as the South African people, to a life spent in service of the people of this country and in the cause of humanity worldwide," president Jacob Zuma said at the central bank offices.

He said that Mr Mandela's release after 27 years in prison for fighting apartheid "marked the beginning of a new era of hope for our country and the world".

Mr Zuma did not say when the new notes would appear. Mr Mandela's image will appear on all South African notes, which are issued in denominations of 10, 20, 50, 100 and 200 rands, officials said.

Local media had reported that speculation about the government press conference put pressure on the rand, but it revived following reassurance from bank officials that the announcement would not be about interest rates or central bank staff changes.

Mr Mandela, the 93-year-old Nobel Peace prize winner, became South Africa's first black president in 1994. Known affectionately by his clan name, Madiba, he has retired from public life.