The African Development Bank has agreed to an external review of an investigation that found no evidence of wrongdoing by its president, Akinwumi Adesina, after a shareholder dispute over the probe.

As part of the review of the committee’s investigation, the AfDB will also assess its whistle-blower and complaint policies to “avoid situations of this nature in the future.”

Adesina is the only candidate for re-election to a new term this year.

The African Development Bank finally gave in to the demands of the United States, which was dissatisfied with the internal investigation that had totally exonerated Adesina from serious accusations made by a group of whistle blowers such as “unethical behaviour, personal enrichment and favouritism”.

“The independent review shall be conducted by a neutral, high-caliber individual with unquestionable experience, high international reputation and integrity,” the AfDB’s Bureau of the Boards of Governors said in a statement. It was done to ensure all governors agree on how to resolve differing views on the matter, the board said.

Adesina, who was elected in 2015 to head the AfDB, one of the world’s five major multilateral development banks, has been the subject of a series of  accusations since the beginning of the year, which were disclosed in the press in April.

In a detailed report, the “whistleblowers” accused him of favouritism in many senior appointments, especially of Nigerians, of appointing or promoting people suspected or convicted of fraud or corruption, and of granting them comfortable severance packages without sanction.

Adesina has refuted the alleagtions saying that the accusations were lies aimed at blocking his unopposed bid for a second term at the helm of the bank.

The United States had demanded at the end of May that an independent investigation be launched, calling into question, in a scathing letter from US Treasury Secretary Steven Mnuchin, the work of the ethics committee.

“Considering the scope, seriousness and accuracy of the allegations against the Bank’s sole leadership candidate for the next five years, we believe that a more thorough investigation is necessary to ensure that the AfDB president enjoys the full support and confidence of shareholders,” Mr. Mnuchin wrote.

The U.S. has a 6.5% stake in the AfDB, the largest shareholding after Nigeria, which held 9.1%, as of November. The 56-year-old institution allowed non-regional countries to join in 1982, and now has 54 shareholders from Africa and 27 from the Americas, Europe, the Middle East and Asia. Members in October pledged to provide funding that will more than double the AfDB’s capital base to $208 billion.