The story of the arrests of alleged mercenaries in Zimbabwe and Equatorial Guinea raises the question of paying trained operatives to intervene in African disputes.
Mercenaries have been accused of fuelling wars in Africa
Since the start of the era of independence in the 1960s, former soldiers have been hired by foreign governments, rebel movements or even commercial companies to carry out operations that no-one else is capable of performing.
Despite efforts by African governments to stamp out the practice, there seems to be no shortage of men prepared to use their training on behalf of anyone willing to pay the right price.
South African role
The end of apartheid 10 years ago meant a large number of well trained personnel were suddenly on the market, as many whites left the South African army.
There were also a large number of black troops, who had been used by Pretoria down the years to conduct covert operations in Angola, Zambia and further abroad.
Many belonged to the "32 Buffalo Battalion" - as they were known.
Two years ago South Africa was investigating the use of its citizens in Sudan. Then there were reports of South Africans fighting for diamond companies in Sierra Leone.
And then they were flying helicopters in Ivory Coast.
The South African government has expressed its embarrassment over reports that South African mercenaries had been arrested in Equatorial Guinea and Zimbabwe.
Foreign Minister Nkosazana Dlamini-Zuma told reporters it was disturbing to hear that "every time" the world dealt with mercenaries, in Africa in particular, South Africans were among them.
"We definitely do not like the idea that South Africa is a pool for mercenaries," she said.
In 1999 South Africa introduced a law banning its citizens from taking part in mercenary acts abroad.
The South African correspondent for Jane's Defence Weekly, Helmoed Heitman, told the BBC that the introduction of this new legislation has made it more difficult to find mercenaries in the country.
"But there are still ways and means to get together, these days probably primarily by email," he said.
But South Africa is by no means the only source for mercenaries. Others have come from European or US specialist units.
In recent years the major development in freelance fighting for profit has been the appearance of private military companies which offer their services to governments and to commercial companies.
The best known of these was Executive Outcomes (EO) - initially based in South Africa and involved in Angola and Sierra Leone.
In Angola, EO employed former South African soldiers and was paid by the Angolan state oil company, Sonangol, to assist the Angolan army in regaining control of the Soyo oilfields from Unita rebels.
It is estimated that EO was paid $40m for its services.
The same company was later involved in supporting the Sierra Leone Government in its attempts to defeat rebels.
The British-based company Sandline also helped Sierra Leone fight the Revolutionary United Front rebels.
Michael Grunberg, a commercial adviser for Sandline, told BBC News Online that private military companies like Sandline see themselves as different from the old image of mercenaries.
"We are established entities, have established sets of principles and employ professional people."
He said Sandline operated as a commercial company and wanted to have a reputation that would enhance its business position.
He emphasised that it would not accept contracts from groups or governments that would risk damaging its commercial reputation.
The old guard
But despite this new image, old-style mercenaries have not disappeared and the depressing cycle of wars in the continent means that there are plenty of places for them to fight and new wars that produce new generations of hired guns.
They are accused of atrocities, of fuelling conflicts and of being beyond anyone's control.
A UK company was warned against sending mercenaries to Ivory Coast
One military source who wanted to remain anonymous, told BBC News Online that mercenaries were still very active and could command $10-20,000 a month for their services.
In April 2003, British Foreign Secretary Jack Straw warned a UK company against recruiting mercenaries to work in Ivory Coast.
He said he was gravely concerned at reports that Northbridge Services Group - a security company - was recruiting ex-servicemen from Britain, South Africa and France.
The company denied that it was involved in such activities.
The BBC's Martin Plaut and Keith Somerville contributed to this report.