Annual credit card spending of €10,030 a year at a charity for people with a serious brain conditions included purchases of alcohol, supermarket food, vouchers, and payment of mobile bills, according to an inspector's report.
The credit card was mainly used by Barbara Flynn, the chief executive of the charity Ataxia Ireland, the investigation by the Charities' Regulator revealed.
The organisation was set up to support people with ataxia - a group of disorders that affect co-ordination balance and speech. But the report warned it had weak internal controls over credit cards, expenses and petty cash.
The investigation found two former trustees - Clare and Tim Creedon, who founded the charity in 1980 - were wrongly paid €84,009.
Charity trustees are barred from payments, except for expenses.
Ms Flynn, who is their daughter, did not inform the charity's other trustees about these payments between January 2014 and June 2015.
The investigators discovered other financial management failures at the charity between 2014 and mid-June 2015.
It paid Ms Flynn's employee pension contributions of €38,500 - rather than deducting it from her salary. The same irregularity, involving €900, was found in the case of another employee.
The payments to Mr Creedon amounted to €600 a month while his wife got €330 a month.
Both claimed the payments were for office and administrative work.
They resigned as trustees in June 2015. Payments were made up to March of that year in one case and April 2016 in another.
The investigation found Ms Flynn continued to operate in her role while "in the full knowledge" the payments to her parents contravened Revenue Commissioner rules.
Eight of the nine former charity trustees who served alongside the Creedons on the management committee were not aware of the payments from January 2014 to June 2015. The one trustee who was aware only found out when they quizzed the charity's accountant.
The investigation found the charity had a €52,744 surplus for the year ending 2015 and net assets of €338,482.
The HSE gives funding of around €113,000 a year and the charity also receives money from lottery grants through the Department of Justice as well as fundraising and member contributions.
It has received more than €300,000 in lottery funding since 2011.
The concerns about the finances only came to light through an internal whistleblower and were first revealed on Independent.ie.
Charities Regulator John Farrelly has written to the trustees requiring a series of corrective actions and wants the overpayments to be recovered.
They have been given 21 days to respond to him.
"If we are not satisfied with the response from the charity trustees, we reserve the right to intervene under section 74 of the Charities Act 2009 to ensure the charity is protected," he said. He has the power to apply to the High Court for a range of measures to protect a charity.
The Creedons founded the charity, first called the Friedreich's Ataxia Society, after two of their children were diagnosed with the condition.
The regulator's instructions include:
Develop, document and implement suitable procedures for the recruitment of senior roles;
Implement more formal monitoring and reporting arrangements in respect of the role of the chief executive;
Agree and implement a formal arrangement with the chief executive to recover the overpayment of employee pension contributions.
The charity did not respond to requests yesterday. It is the latest charity to be at the centre of an investigation over irregularities and it follows revelations about Console last year.