Judge Hefer found no evidence to back up the allegations

Retired judge Joos Hefer ruled that there was no evidence to support the allegations, which had led to him conducting an official inquiry.

Bulelani Ngcuka had told the inquiry that the accusations were designed to discredit his work.

They surfaced after he investigated allegations of corruption against Vice President Jacob Zuma.

"Mr Ngcuka probably never acted as an agent for a pre-1994 government security service... the allegations of spying have not been established," Judge Hefer said.

The director of public prosecutions has led several investigations into high profile corruption cases.

Proceedings of the inquiry were televised live in South Africa. It has been suggested by commentators in South Africa that the inquiry is part of a power struggle about who should succeed President Thabo Mbeki in the ruling African National Congress.

Cross-examination

Mr Zuma, a favourite to succeed Mr Mbeki, was alleged to have been involved in a corrupt multi-million dollar arms deal.

Mr Ngcuka announced there was prima facie evidence to suspect Mr Zuma, but not enough to prosecute him.

Mr Zuma angrily responded that his reputation was being tarnished, but he was not being given the opportunity to clear his name in court.

BULELANI NGCUKA Unknown in 1994 Pledged to fight corruption Secured conviction of Winnie Mandela Accused of spying for apartheid Full profile

The spying allegations surfaced shortly afterwards and President Thabo Mbeki set up the Hefer Commission.

Mr Ngcuka's two main accusers are former Transport Minister Mac Maharaj and former ANC intelligence agent Mo Shaik.

Mr Maharaj is currently under investigation by the elite Scorpions police unit on suspicion of being linked with a corrupt deal when he was a minister.

And Mo Shaik's brother, Shabir Shaik is facing charges of corruption linked to the government's controversial arms procurement deal.

After gruelling cross-examination, neither man produced any proof to back up their allegations.