MTN has become embroiled in rumours of corruption, following its purchase of Ghanaian cellular phone company Areeba.
Reports allege that Areeba's previous owner, Scancom Ghana, was involved in smuggling millions of dollars out of Ghana, according to Sake24.
An investigation of Scancom has brought allegations of money laundering, tax evasion and balance sheet fraud to light.
Questions have also been raised about the company's financial operations and its takeover by MTN.
The country's unit against serious corruption and fraud is calling for billions of rands to be repaid by Scancom. These amounts would include funds acquired wrongfully, dividends and profits from the MTN buyout.
MTN is not implicated in the corruption charges.