(Ecofin Agency) - The South African telecom group MTN has just been sullied by an investigation by "Finance Uncovered".

The network of journalists from 55 countries worldwide, accused four subsidiaries of the multinational company - MTN Côte d'Ivoire, Ghana, Nigeria and Uganda - of tax avoidance. These branches have supposedly transferred over many years hundreds of millions of dollars to offshore companies based in Dubai and Mauritius.

In the 2-year investigation, published in the South African newspaper Mail and Guardian, Ugandan The Observer and the Ghana Business News, "Finance Uncovered" reveals that between 2003 and 2009, MTN Uganda transferred 3% of its revenue to MTN International based in Mauritius, same for MTN Côte d'Ivoire who sent 5% of its 2013 revenue. It was mentioned that the Mauritian subsidiary is just a postal address with no employee. MTN Ghana paid 9.64% of its revenue to MTN Dubai, the same for MTN Nigeria with USD 562 million paid between 2010 and 2013. These payments decreased the revenues of the subsidiaries as well as the income tax to pay to the countries where they operate.

In a press release, the MTN group hammered home that under no circumstances was the company "involved in a plan aimed at helping the company to avoid its legal and tax responsibilities, in none of the jurisdictions where we operate".

It is worth noting that out of all the MTN subsidiaries in Africa, the Ugandan branch has been fighting tax evasion accusations since 2012, originating from many anonymous denunciations. But the charges have always been dropped by the public prosecutor due lack of proof.