Minister for Small Business in NSW Janelle Saffin announced on Friday that her office had completed an audit of its travel expenses and found she had mistakenly paid for official travel to Sydney using her ministerial office budget.
Ministers cannot claim expenses incurred during travel to Sydney from their ministerial budget, as Sydney is considered the headquarters of all ministers.
Instead, MPs from non-metropolitan electorates are given a Sydney allowance they can use to cover hotel stays when travelling to the capital to the tune of approximately $390 a night.
Ms Saffin confirmed that she will reimburse her ministerial office budget for the expenses and will seek to claim some of her expenses via the Sydney allowance instead.
Among her expenses were $24,000 in hotel stays, including eight nights at Sydney's Sofitel for $650 a night during Sydney's Mardi Gras, and $13,500 on flights.
"I regret that this administrative error was not picked up and rectified sooner but I hope my experience will result in greater awareness of Ministerial and MPs' entitlements for everyone," Ms Saffin said.
"I strongly believe regional MPs should be able to serve as Ministers. Regional communities deserve a strong voice around the Cabinet table, and the practical reality of living outside Sydney should never be a barrier to that."
Premier Chris Minns said on Thursday that he had spoken to Ms Saffin about her hotel bills, but would not comment further before the findings of the audit had been released.
Opposition leader Kellie Sloane said all ministers had an obligation to ensure their expenses were coming out of the appropriate account.
"She needs to get her accounting right, and she needs to be clear and honest with the people of New South Wales ... taxpayers need to have confidence that ministers in this government right now are doing the right thing by taxpayers."