A South African spokesman, Tony Trew, said Mr Mandela met the fugitive ex-leader on Wednesday with the knowledge of the Zimbabwean government.

The private meeting took place in Pretoria at the request of Banana, who "wanted to inform the president he was in the country".

The spokesman said Banana made no request for asylum and said he would not be in the country long.

Zimbabwean police have called on their South African counterparts to help them trace the 62-year-old Methodist clergyman.

He slipped out of Zimbabwe last week, days before being convicted in absentia of 11 charges, including homosexual assault.

He was located in Botswana last week and Zimbabwean newspapers reported that he could be headed for South Africa, where his son works.

Further arrests possible

Zimbabwean officials say Banana could also face a charge of leaving the country illegally.

His passport was handed over to Zimbabwean authorities as part of his bail conditions during the trial, at which he pleaded not guilty to all charges.

Banana retired as president in 1987 when he was succeeded by Robert Mugabe.

His trial only went ahead in June this year after the Supreme Court rejected his appeal that adverse pre-trial publicity had prejudiced his right to a fair hearing.

Mr Banana denied allegations that he ever sodomised or tried to sexually attack his aides-de-camp, guards and cook or two other men he picked up on the streets.

Sodomy is illegal in Zimbabwe and punishment includes fines and jail terms of up to two years.

Observers say the case has deeply embarrassed President Robert Mugabe, who insists homosexuality is foreign to African culture and was brought to the continent from the West.

Some other African countries have taken a similar stance, but in South Africa, homosexual sex has recently been decriminalised.