The discovery was reported after a review led by law firm Glaser Weil and Freeh Group International Solutions, which was appointed in January following allegations of accounting irregularities from a market analyst. 

Meanwhile, early results from a PwC investigation into accounting practices at provider NMC Health, sparked by the discovery of $335m (£259m) in undisclosed loans to related parties, have unearthed over $2.7bn (£2bn) in undisclosed debt.

The Abu Dhabi-based company, which runs private hospitals and facilities in UAE and 19 other countries, first disclosed problems at the end of last month when it said its year end results would be delayed following an internal review.

In response, at the beginning of March, NMC announced that Moelis & Company, PwC and Allen & Overy had been appointed as independent financial adviser, operational adviser and legal adviser, to look into the issues raised in more detail. PwC’s role was described as assisting on liquidity management and operational measures.

In an update 10 days after the appointment, the board said PwC and Moelis had reported that the group’s debt position was materially above the last reported number as at 30 June 2019, and is currently estimated to be around $5bn. The work on verifying this figure is ongoing.

In addition to $2.1bn group debt reported at 30 June 2019, the company has identified over $2.7bn in facilities that had previously not been disclosed to or approved by the board.

In an update, the company stated: ‘NMC is continuing to work with its advisers to understand the exact nature and quantum of the undisclosed facilities. The board believes that some proceeds may have been utilised for non-group purposes.’

The original internal review identified supply chain financing arrangements between NMC Health and entities controlled by the company’s founder, Bavaguthu Shetty, and Khaleefa Butti Al Muhairi, who was executive vice-chairman.

Under these arrangements, suppliers to these companies were paid by certain credit facility providers and, while those companies are responsible for settling the amounts payable to the credit facility providers, the contractual obligation rests with NMC, which has also provided a guarantee in the event of non-payment or default.

The facilities have been in place since early 2018. The drawdown on the facilities as at 31 December 2019 was estimated at approximately $335m and was not disclosed to, or approved by, NMC Health’s board and not disclosed as related party transactions in accordance with the listing rules.

The arrangements were not reflected on the company's balance sheet nor reported in its financial statements for the financial year ended on 31 December 2018.