The Ghana Revenue Authority (GRA) is asking some of the nation’s largest companies to pay millions of dollars in back taxes as the cash-strapped government scrambles to raise money and finalise a bailout from the International Monetary Fund (IMF).

The largest wireless provider in Africa, MTN Group Ltd., as well as Tullow Oil Plc and Gold Fields Ltd., have all been informed that they owe past taxes.

The assertions of the government are refuted by all of the businesses.

The majority of the government's income must now go toward paying down the estimated 576 billion cedis ($48 billion) in public debt.

“Ghana is clearly facing fiscal and economic challenges at the moment,” Gold Fields spokesman Sven Lunsche said in an emailed response to questions.

“We are hopeful that the government will not resort to unreasonable fiscal measures that will further imperil the challenges facing the corporate sector.”

West Africa’s second-largest economy lost access to international capital markets because of its ballooning debt and loan service costs.

It’s restructuring most of its obligations amid a slump in the cedi, and is seeking a $3 billion loan from the IMF. 

Gold Fields is in talks with the country’s tax authority to try and resolve the demand for 2018 to 2020. MTN, which has been ordered to pay $776 million, has until Friday to reach an agreement with the Ghanaian authorities.

Dallas-based Kosmos Energy stated that the government alleged it had failed to meet its contractual tax and financial obligations.

The assertion is false, and if necessary, Kosmos will "vigorously dispute" it. Kosmos and Gold Fields both declined to provide financial information.

When contacted by phone, a spokesperson for the Ghana Revenue Authority declined to comment.