By Martin Plaut
BBC News Africa analyst
Tony Blair may have some explaining to do over a major arms deal with South Africa on the last leg of his week-long Africa tour.
Tony Blair visited South Africa on two occasions in 1999
One awkward question which may not be on Mr Blair's agenda during this week's visit to South Africa will be his role in helping a leading British arms supplier to win a multi-million dollar arms contract.
The deal, signed by BAE, was part of a much larger arms procurement programme, with contracts signed by a range of European companies.
Some of these contracts have become bogged down in controversy.
And more recently it has also been alleged that BAE itself paid what have been termed "commissions" to ensure that it won the contract.
While there is no suggestion that the prime minister knew of or participated in any wrongdoing, his role in supporting the BAE bid has never been fully explained.
In 1999, the year in which the arms deal was signed, Tony Blair visited South Africa twice.
According to the Foreign Office this was in January and November. Since then Mr Blair has only been in South Africa once, in February 2006.
Back in 1999 the South African press carried very little that even hinted that an arms contract was part of the reason Mr Blair visited the country.
The deal was the largest South Africa had ever concluded, re-arming the country after the end of the arms embargo that had been in place during the apartheid years.
It was worth $4.8bn and included the purchase of corvettes, submarines, light utility helicopters, lead-in fighter trainers and advanced light fighter aircraft.
The BAE share of the arms procurement contract was to supply 24 Hawk advanced jet trainer aircraft, while Swedish manufacturer Saab, which is part-owned by BAE Systems, was to supply 28 Gripen fighter planes.
The entire arms deal was questioned by critics when it was being drawn up. They argued that South Africa, as a young democracy, had more pressing problems.
These concerns were swept aside by the ANC government. But soon other concerns arose.
The overall deal soon became bogged down in controversy, with allegations that bribes had been paid to win the contracts which involved a number of European suppliers.
The former ANC chief whip, Tony Yengeni, was one of the first in the spotlight after he started driving around Cape Town in his state-of-the-art dark green Mercedes Benz ML320 4x4 with its tinted windows and plush beige upholstery.
In 2004, Yengeni was convicted of defrauding parliament by accepted a discount on the car. He was jailed in August 2006 but was released on parole after completing just five months of the four-year sentence.
Then Schabir Shaik, financial adviser to the South African deputy president, Jacob Zuma, was jailed for 15 years for soliciting a bribe for Mr Zuma from Thales.
And in June 2005 Mr Zuma was sacked from his position as deputy president, while further charges against him continue to be investigated by the South African authorities. Mr Zuma has repeatedly denied any wrongdoing.
None of these convictions or allegations involved BAE.
But now it has been reported that the UK's Serious Fraud Office (SFO) has asked its South African counterpart, the National Prosecuting Authority (NPA), to help it track down more than $139m in "commissions", allegedly paid by BAE to eight South African businesses and a political adviser.
The prime minister could face a stormy time in South Africa
The NPA has also been probing the deal and confirmed that a request had been received, "which was being processed".
These questions were pursued at the BAE AGM earlier this month, when a former ANC member of parliament, Andrew Feinstein, used the meeting to raise a series of questions.
He asked the BAE chairman Dick Oliver: "Give this meeting an assurance that not one penny found its way into the hands of one South African official or politician.
"One senior ANC executive committee member told me the 1999 election campaign was funded from the proceeds of the arms sale."
Mr Oliver declined to comment on Feinstein's specific allegations, saying an SFO investigation into similar claims was ongoing.
He added: "You can be assured all information is being passed and help is being offered in a fulsome way."
One other area that has remained controversial is the number of jobs that the deal has created for South Africa.
It was claimed in 1999 that it would produce 65,000 jobs, but so far only a fraction of those have appeared.
There have also been reports that South African President Thabo Mbeki is furious that while an investigation into the BAE arms deal with Saudi Arabia was ended after the attorney general decided that it was "not in the public interest" no such decision has been taken over the South African deal.
Speaking at the World Economic Forum in Davos earlier this year, Mr Mbeki said: "It does puzzle me why a strategic interest with regard to the work of BAE, there would be a strategic interest that would arise with one country and does not arise with other countries."
Mr Blair may have some explaining to do when he meets his host in South Africa this week.