(Bloomberg) — NMC Health Plc hired former FBI Director Louis Freeh to investigate allegations by short seller Muddy Waters Capital LLC of financial wrongdoing by the hospital operator.

The appointment is part of NMC’s effort to restore investor confidence. The company’s shares have plunged 44% since Muddy Waters said in a Dec. 17 report that NMC’s financial statements hint at potential overpayment for assets, inflated cash balances and understated debt. The stock rose as much as 7.8% Friday in London.

NMC, which previously called the allegations “unfounded, baseless and misleading,” last month appointed a committee of independent board members to look into the matter. The panel is focusing its review initially on confirmation of the company’s cash balances as of Dec. 15, the United Arab Emirates-based company said in a statement Friday.

“The committee chose Freeh Group to provide a completely independent, unbiased, comprehensive and transparent report that will address all of these allegations,” said Jonathan Bomford, chairman of the committee.

Muddy Waters, led by Carson Block, also alleged that NMC’s independent directors aren’t truly independent, and that the company appears to be doing business with entities controlled by its leading shareholders without properly disclosing it.

The short-selling firm made headlines last year with reports criticizing both NMC and Burford Capital Ltd., a litigation-finance company. Muddy Waters has also issued critical reports on companies including French retailer Casino-Guichard Perrachon SA.

Freeh, a former FBI agent and federal judge, ran the U.S. law-enforcement agency from 1993 to 2001. His risk-management firm, Freeh Group International Solutions LLC, includes former senior law enforcement officials, accountants and security and compliance experts. He also runs an affiliated law firm.

His corporate clients have included Wynn Resorts Ltd., cryptocurrency firm Tether Ltd. and a pharmaceutical-industry group.

“We had expected NMC to appoint an accounting firm, but it may have opted for a third party with a wider range of expertise given the governance-related allegations made against it,” Morgan Stanley analyst Saul Rans said in a report.

NMC climbed 6% to 1,528.50 pence at 8:17 a.m. in London.

–With assistance from Lisa Pham.