Two major NMC Health PLC shareholders sold £375 million worth of the company's common stock, putting a strain on the Middle Eastern healthcare services provider's share price, Reuters reported.

NMC shares were trading at £12.575 as of 5:06 p.m. London time, down 15.86%.

The share sale by the firm's Vice Chairman Khaleefa Al Muhairi and its second-largest shareholder Saeed Al Qebaisi follows a report by U.S. short-selling firm Muddy Waters LLC last month, accusing the company of a number of deficiencies. NMC responded to the report at the time by starting an independent third-party review of its business, though denied any wrongdoing on its part — calling the report false and misleading.

The two investors sold some of their holdings to repay debt, Reuters reported, citing the bookrunner involved in the sale. Shares were sold at £12 each, or at a 20% discount to NMC's previous closing price, accounting for the events surrounding United Arab Emirates' largest private healthcare provider.

NMC said the sale was not related to its performance.

Muhairi will retain a 12.5% stake in NMC, while Qebaisi will keep a 4.7% holding. The investors jointly hold roughly an additional 7% in NMC through an entity called Infinite Investment.

While NMC's stock started recovering after it said it would start an independent review of the business, it has still lost nearly £3 billion in market value since the release of Muddy's report on Dec. 17, 2019.