Former Garda Commissioner Nóirín O'Sullivan has been appointed as the UN's Assistant Secretary-General for Safety and Security.
Ms O'Sullivan retired from the gardai in September 2017 following a number of controversies in the force.
The Disclosure's Tribunal recently found she had no hand, act or part to play in any smear campaign against garda whistleblower Maurice McCabe.
She began her career with An Garda Síochána in June 1981 and progressed through the ranks.
In her new role, Ms O'Sullivan will serve as deputy to the Under-Secretary-General for Safety and Security in providing support as well as will being responsible for the day-to-day management of the Department.