The head of the United Nations Relief and Works Agency for Palestine Refugees in the Near East (UNRWA) has stepped down.
Pierre Krähenbühl is being investigated by the UN's Office of Internal Oversight Services (OIOS).
It said on Wednesday it had completed a part of the ongoing inquiry into UNRWA management-related matters.
In a statement, it said: "The findings of OIOS revealed management issues which relate specifically to the Commissioner-General [Krähenbühl].
"The Commissioner-General has stepped aside until the completion of the process.
"The UN Secretary-General has appointed Mr Christian Saunders as the officer-in-charge for the interim period."
Over the last few months, UNRWA has initiated an internal review of its governance, management and accountability functions.
The review revealed a number of areas which required strengthening, it said.
The agency has already started corrective action and said it will be pursuing further initiatives and improvements over the coming months.
"UNRWA is grateful for the critical support of UN member states and other partners around the world and is committed to ensuring donor funds are utilised in the most efficient and effective manner in support of the agency's critical mission", it added.
An internal ethics report accused Mr Krähenbühl and his "inner circle" of "abuses of authority for personal gain, to suppress legitimate dissent and to otherwise achieve their personal objectives", according to Al Jazeera.
The report alleged that the individuals' reported conduct presented "an enormous risk to the reputation of the UN" and that "their immediate removal should be carefully considered".
Others named included deputy commissioner-general Sandra Mitchell - who resigned from her post in late July - and chief of staff Hakam Shahwan - who left the agency in early July.