Rehab has published its Annual Report for 2014, detailing losses of over €6 million and the loss of 50 jobs.
The financial statement also shows that a handful of people who left Rehab received large pension pay-outs, one of them in the region of €320,000.
Two members of staff have had their names redacted from the document.
The Charity appointed a new Chief Executive in January of this year, Mo Flynn.
In the Annual Report she has outlined a commitment to ensure transparency and accountability going forward.
Chairman Sean Egan writes: "These failings constituted a serious breach of trust, and the organisation’s reputation was significantly damaged as a result."
As part of steps Rehab is taking to transform its operations, the group has reduced senior pay by an average of 18%, and set a new salary cap of €140,000 for the Chief Executive.
13 new Board members were appointed in September 2014, after a public recruitment process. Two former Board members were retained.
Deirdre Garvey is CEO of Charities organisation The Wheel. She told Newstalk Breakfast Rehab is not typical of the kind of charity operating in Ireland.
She says its €160 million income, as described in the report, shows it was operating on a completely different scale:
