The Gay and Lesbian Equality Network - known as GLEN - is to be wound up, the organisation has confirmed.
The board of the organisation said it is not possible to return the charity to "full, financial viability while maintaining existing services".
It comes less than a month after GLEN appointed Jillian van Turnhout to carry out a comprehensive review of the organisation.
The review came amid concerns over the use of funds for non-GLEN political campaigns and the use of company credit cards for private purposes.
The Irish Times reports that Ms van Turnhout's report found the use of credit cards for personal purposes was “extremely poor practice” - but added there was no material gain to any staff member or any other person.
A separate financial review "did not find any evidence of misappropriation of state or donors funds or any fraudulent activity taking place”.
In a statement this morning, GLEN confirmed that it had accepted the recommendations of Ms van Turnhout.
The charity's board says: "Following a comprehensive external review of the operation of GLEN the board has reluctantly concluded that we do not currently have the organisational capacity or funding to continue our work to the high standard to which we have always aspired.
"The only reason why GLEN exists is to serve the best interests of the LGBTI community. We believe that the needs of the community can best be met by the transfer of key services to other agencies as soon as possible."
The board is aiming to ensure services GLEN currently offers - including an LGBT helpline - will be provided by other organisations.
Redundancy notices have been served on three employees, the statement adds.
GLEN - which was established in 1988 - is currently being reviewed by the Charities Regulator, but the board stresses that no investigation has been commenced by the regulator.
Today's statement acknowledges a "proud record of achievement in serving the LGBTI community".
The statement adds: "We have delivered not just a range of services; we have also helped radically reshape the lives of LGBTI people through the achievement of progressive social change, culminating in the successful Marriage Equality campaign in 2015."
