JOHANNESBURG - Former South African President Nelson Mandela has been discharged from hospital, ending a nearly three-week stay during which he was treated for a lung infection and had surgery to remove gallstones, the government said on Wednesday.

The 94-year-old anti-apartheid leader and Nobel Peace Prize laureate has been moved to his Johannesburg home. He has been in frail health for several years.

Former South African President Nelson Mandela poses for photographers prior to a charity dinner in Vienna in this Oct 22, 2003 file photo. [Photo/Agencies]?

"We request a continuation of the privacy consideration in order to allow for the best possible conditions for full recovery," it said, without offering further details.

Mandela has a history of lung problems dating back to when he contracted tuberculosis while in jail as a political prisoner. He spent 27 years in prison, including 18 years on the windswept Robben Island off Cape Town.

The former president was admitted to a Pretoria hospital on December 8 and this was his longest stay in hospital since he was released from prison in 1990.

Current President Jacob Zuma visited Mandela on Christmas Day and said the former South African leader was doing much better, making progress and in good spirits.

Mandela was also admitted to hospital in February because of abdominal pain but released the following day after a keyhole examination showed there was nothing seriously wrong with him.

He has spent most of his time since then in another home in Qunu, his ancestral village in the impoverished Eastern Cape province.

His poor health has prevented him from making any public appearances in the past two years, although he has continued to receive high-profile visitors, including former US President Bill Clinton earlier this year.

Mandela became South Africa's first black president after the country's first all-race elections in 1994.

After his release from prison, he used his popularity to push for reconciliation between whites and blacks, which became the bedrock of the post-apartheid "Rainbow Nation".

Mandela stepped down as president in 1999 after one term in office and has largely been absent from public life for the last decade.