According to a Nigeria Communications Week report, embattled South African telephone operator MTN Group and French-owned Orange were charged $160 million in Cameroon for failing to pay taxes on games and gambling services.

In a report written by the central African country’s anti-corruption commission, known as CONAC, MTN and Orange were also accused of allegedly not paying taxes on their money transfer system, known as Mobile Money.

CONAC said a wide-reaching probe into the sector led to fines totaling $283 million, and found other companies, including Camtel and Viettel, were also in violation of regulations.

The amount paid by each company was not indicated in the report but Reuters reported CONAC saying MTN owed nearly 52 billion CFA francs in taxes and royalties, while Orange was supposed to pay around 48 billion CFA francs.

MTN’s unit in Cameroon has said in a statement sent on Friday that it “IS NOT AND HAS NEVER BEEN implicated in corruption-related actions in the exercise of its activities”.

“MTN Cameroon is a responsible investor and is up to date with regard to its fiscal obligations to the relevant authorities in Cameroon, in accordance with all applicable rules and regulations,” the operator said.

“Our company is one of the two biggest contributors to the State in terms of taxes and customs duties.”

The fine is another blow to MTN, which is already negotiating to have a record $5.2 billion fine it was charged by the Nigeria Communication Commission (NCC) in October for allowing unregistered SIM cards on its network after a September deadline expired.

The fine has since been reduced 25 percent to $3.9 billion. Negations are still ongoing and on Friday a Nigerian court postponed its hearing to allow both parties to see if they can settle out of court.