Angola's largest telecommunications group Unitel has been included in a list of companies reportedly used by entrepreneur Isabel dos Santos to exploit resources and expropriate funds.

Dos Santos has been described as Africa's richest woman, with investments in both Angolan and international companies spanning telecoms, oil and banking, among other sectors.

She is also a major shareholder in Unitel, Angola's biggest mobile operator with plans to expand to Zambia.

Dos Santos is now at the centre of a financial scandal after the Platform to Protect Whistleblowers in Africa (PPLAAF) shared leaked documents, under the auspices of what is being called #LuandaLeaks, with the International Consortium of Investigative Journalists (ICIJ).

The documents implicate Dos Santos as having irregularly arranged for Unitel to lend €350-million to a company in which she is alleged to have interests.

The information reportedly shows that Dos Santos signed off both for the lender and borrower companies. The borrower has been identified as Unitel International and is said to be controlled by Dos Santos.

Dos Santos responded to the ICIJ #LuandaLeaks via her legal representatives and stated: "The Unitel Board of Directors approved Unitel's loans to Unitel International. Any allegation that the loans amounted to looting of public money is false... as Unitel is privately funded and does not have recourse to public funds."

The BBC reported on Monday that "Unitel has already paid her $1bn in dividends" while her stake in the telecom company is worth another $1bn. It added: "The company name (Unitel International) was misleading because it wasn't connected to Unitel and Ms Dos Santos was the owner."

Dos Santos' lawyers continued: "... the loans to Unitel International served an important financial purpose for Unitel, because Unitel used them to hedge against devaluation of Angolan Kwanza which is frequently subject to sudden and significant changes in value."

However, the ICIJ asserts that Unitel could not prove that its board had approved the loans to Unitel International.

ICIJ has also reported that Dos Santos said she had learned through a WhatsApp group that her personal bank accounts had been frozen.

"A court in Angola had frozen her personal bank accounts, those of her husband and her stakes in some of the country's largest companies, including phone provider Unitel," noted ICIJ in its investigative report.

Forbes Magazine online has previously reported that: "Every major Angolan investment held by Dos Santos stems either from taking a chunk of a company that wants to do business in the country or from a stroke of the president's pen that cut her into the action."