Local units of telecom companies MTN and Orange have been fined over $160 million by Cameroonian authorities for failing to pay taxes on games and gambling services.

Cameroon’s anti-corruption board, known as CONAC, stated this after concluding a wide-reaching probe into the country’s telecoms sector.

According to a report from CONAC, MTN owed nearly $86 million in taxes and royalties, while Orange should pay around $79 million.

It said both companies had also benefited from tax breaks –over $46 million for Orange and $39 million for MTN – that the corruption watchdog deemed to be illegal.

The investigation also discovered that other companies including Camtel and Viettel were in violation of regulations, leading to fines of about $283 million in total.

The report also accused MTN and Orange of not paying taxes on their money transfer system, known as Mobile Money.

However both companies have denied evading tax in the Central African country.

“Orange has not received any formal notification of the conclusions of a report or a fine of any sort. We are not aware of this affair,” an Orange spokesman said.

MTN also said it had not been informed of any fines against its Cameroon business, but said it was looking into the matter.

“MTN Cameroon is not and has never been implicated in corruption-related actions, in the exercise of its activities,” the company said in a statement.

The other companies are yet to issue a statement.

The report is another blow for MTN, which is currently contesting a $3.9 billion fine levelled against it in Nigeria for failing to disconnect users with unregistered SIM cards.

The Nigerian government, which currently faces threat from the Boko Haram militant group, is quite concerned that unregistered SIM cards can be used for criminal activity in the country.

MTN successfully lobbied to get the fine reduced from $5.2 billion to $3.9 billion in December. The matter is still in court and it’s unknown if MTN will have to pay the fine.