The Paradise Papers is a new major data leak of 13.4 million confidential files, most of which are related to the Bermuda law firm, Appleby. A group of media organizations is collaborating to investigate the documents, coordinated by the International Consortium of Investigative Journalists. 

The leak shows just how many of Africa's rich and powerful – from the head of Nigeria's Senate, Bukola Saraki, to Ellen Johnson Sirleaf, the president of Liberia – park their money in offshore havens. 

It also raises the moral question of whether it is legitimate for the continent's elites to avoid paying taxes while the majority of Africans live below the poverty line, says Peter Jones from Global Witness, an NGO dedicated to tackling resource corruption. 

At the same time, he says, it's important to remember that tax havens are also secret jurisdictions that can easily hide criminal activity, he said, from bribery to money laundering.  

"Companies set up in these places hide their real owners. You can't find out very much information about who is behind them, about what the business does, or what capital it has," Jones told DW. 

Paper trail to disreputable dealings in the Democratic Republic of Congo

In the past few years, numerous investigations have detailed the cronyism and corruption in the mining sector that have left DR Congo as one of the world's poorest countries despite its mineral wealth. What's new in the Paradise Papers is detailed evidence of some of these shady dealings. 

In 2008, the Swiss-British mining giant Glencore loaned $45 million (38.7 million euro) to Dan Gertler, an Israeli middleman close to DR Congo's president, Joseph Kabila. The loan was conditional on Gertler successfully negotiating a new deal with Congo's government for a mine in which Glencore had a stake. The deal enabled Glencore to take over the Katanga copper mine, with Gertler also buying a stake - directly financed by the Glencore loan. 

""The loan was really a kind of reward scheme," Jones from Global Witness told DW. "Gertler provides his services, which is apparently access to power, and in return he gets these little bonuses like being loaned the money to take part in the takeover."

"This is a story about how huge companies can go into environments where there isn't much regulation and hide the kinds of deals that they are striking by using offshore companies and vehicles," Jones said. "And that means they can get away with deals that can prove quite damaging to the countries they work in."

A 2013 report estimated DR Congo lost 1.4 billion dollars because it sold its resources below value. 

Shining a light on Angola's oil fund

Angola's sovereign wealth fund was created to great fanfare in 2012 to invest the country's vast oil profits for the benefit of the people. The Paradise Papers reveal that one of the fund's managers is using its money to invest in his own businesses. 

Jean-Claude Bastos, a Swiss-Angolan entrepreneur, administers the majority of Angola's $5 billion wealth fund through his company, Quantum Global. According to investigations by the Guardian newspaper, one of the consortium members, Bastos has invested capital from Angola's wealth fund in at least four assets that he controls. The entrepreneur has denied that this is a conflict of interest. 

Bastos, who was previously convicted in Switzerland of illegally paying investment monies into his own pockets, won the contract to manage most of the fund without any competitive tender. Interestingly, the fund's chairperson is Jose Filomeno dos Santos, who is not only the son of Angola's former president Jose Eduardo dos Santos but also a friend of Bastos. 

Read more: The future is bright for Angola's dos Santos clan

This cozy arrangement is further fuel to the fire in a country where the elite control much of the country's wealth and resources. Raul Danda, the parliamentary leader of UNITA, the main opposition party, told DW that someone who has been convicted of breaking the law "shouldn't be trusted with the money of the Congolese people."

"I note a large lack of transparency in this management," Danda said. 

Speaking to DW, Angolan journalist and anti-corruption activist Rafael Marques called Bastos "a big swindler" who together with Jose Filomeno was "robbing the fund of money that belongs to the Angolan people." 

Angola's new President Joao Lourenco is also in a gold mining partnership with Bastos in Huila province, Marques pointed out. 

Uganda, Ghana and the rest 

Because of the international scope of these dealings, the cases of DR Congo and Angola in the Paradise Papers have received much media attention. But the leak also reveals that leaders in other African countries are among those with offshore companies. 

For instance, Uganda's foreign minister and former UN General Assembly president, Sam Kutesa, set up an offshore trust in the Seychelles, a haven for bank secrecy, to manage his personal wealth. 

In Nigeria, the President of the Senate, Bukola Saraki, has a company registered in the offshore tax have of the Cayman Islands. According to Nigeria's Premium Times, a member of the consortium evaluating the Paradise Papers, Saraki failed to list this company on his assets declaration when be became governor of Kwara State in 2003. 

And in Ghana, the brother of the country's ex-President, John Dramani Mahama, is among those named in the papers for wanting to open offshore companies on the Isle of Man. 

Additional reporting by Thiago Melo and Philipp Sandner