Labour Party MP Ruth Dyson says she is paying back a $16,000 taxpayer subsidy she received for a private overseas trip.
The MP and her husband returned from the three-week trip to Ethiopia on Sunday.
Ms Dyson was eligible for a 90% travel subsidy on the trip because of the length of time she has been in Parliament and applied for the funding in June last year.
At the time, there was heightened public awareness about MPs' spending and travel perks.
Since then, the rules have changed and the international rebate for personal travel for sitting MPs has been scrapped.
Ms Dyson says the subsidy she received was completely within the rules but, because of public concern over the matter, the appropriate thing to do is repay the money.
The MP says she felt uncomfortable about the subsidy while on the trip.
Labour leader Phil Goff says she has made the right decision to pay the money back. He says he is not aware of any other Labour MPs recently using the subsidy.
