Under-Secretary-General Nair, who heads the Office for Internal Oversight Services, has a week to respond to the charges raised by the Independent Inquiry Committee which is investigating misconduct and mismanagement in the UN Oil-for-Food Programme for Iraq.
The committee is led by former US Federal Reserve Chairman Paul Volcker.
The Committee accused Nair of paying a special assistant from the Oil-for-Food programme fund, although the person performed no work related to the operation which allowed Iraq under Saddam Hussein to use oil-sale proceeds to purchase specific humanitarian supplies.
The United Nations has also launched an independent review of the allegations made against Nair to determine whether a full investigation is warranted.
Nair will retire as head of OIOS at the conclusion of his non-renewable 5-year term on April 23.