A Health Service Executive audit into the hepatitis C support group Positive Action found "control over the expenditure of public funds was non-existent".
The report, which was released to RTÉ News under Freedom of Information, found there was "significant extravagance" at Positive Action, but "no consideration by the directors of value for public money".
The internal audit, which was completed in 2014 but only released today, concluded that "governance of Positive Action Ltd was seriously flawed".
The release of the report follows last year's sentencing of former Positive Action director Bernadette Warnock to two years in prison.
Warnock had pleaded guilty to stealing over €116,000 from the group, which was set up in 1994 to help women who contracted hepatitis C through contaminated blood products in maternity hospitals.
Positive Action had 730 members and received the majority of its funding from the HSE. It was closed down in 2014 following the HSE audit.
In a series of damning findings, the audit concluded that public funds were "not used economically, efficiently, effectively or appropriately".
The report states that "in excess of 43% of public funds ... were spent on overseas trips, weekends away, dining, expenses of the executive committee members/directors, and complimentary beauty therapies".
The audit concluded: "The impression was created that money was no object and extravagant expenditure was normal."
Warnock, who contracted hepatitis C at the age of 24, had campaigned for a Tribunal of Inquiry into the infections and was influential in having the government set-up a compensation scheme for those affected.
When asked what she spent the money on, Warnock told gardaí: "That's the worst part of it. I have nothing to show from it."