The personal driver of former Ceann Comhairle Sean Barrett claimed over €10,000 in overnight expenses last year.
The Times reports Dominic Hearn, a former garda, was eligible for a €125 untaxed payment for each day worked, as he was not resident in Dublin.
Barrett's commute, from Killiney to Leinster House, is around 15km.
In the year ending January 2016, Hearn claimed €11,301.12 in overnight expenses, which were signed off by Barrett.
As the Ceann Comhairle is no longer entitled to a ministerial car, Barrett had to provide his own car, and was able to hire two drivers and claim for mileage.
Barrett claimed over €48,000 in mileage between his appointment and the end of 2015.
Oireachteas rules allow for overnight expenses for anyone living more than 22.5km from the GPO on Dublin's O'Connell St.