FILE PHOTO: A shopper walks past an MTN shop at mall in Johannesburg
INTERNATIONAL - The office of Nigeria’s attorney general said on Tuesday that a whistleblower prompted an investigation into alleged MTN infractions that last week led to a demand for $8.1 billion taken out of Nigeria to be brought back.

Ladidi Mohammed, head of asset recovery, told Reuters in a phone interview that an investigation was then carried out by the central bank.

The South African telecoms giant in a statement issued on Tuesday said all dividend repatriation out of Nigeria was done on the basis of equity capital and with valid certificates. 

Furthermore, MTN Group has been slapped with a $2 billion tax bill, it said on Tuesday, the latest demand by authorities in the South African company’s most lucrative but increasingly problematic market, sending its shares lower.

The announcement of the tax bill comes days after the west African country’s central bank ordered MTN’s Lagos-based unit hand over $8.1 billion that it said was illegal sent abroad.

In a statement outlining the background to the $8.1 billion that the central bank said MTN Nigerian unit used improperly issued certificates to send abroad, MTN disclosed it had been in talks with Nigeria’s Attorney General about an investigation into tax compliance by the mobile operator.