The aid agency GOAL has said a succession plan is in place and its Chief Executive John O'Shea has been asked to slow down by his family and his doctor.
Speaking to RTÉ's This Week, GOAL Chairman Pat O'Mahoney rejected criticism levelled at the charity by former board member Fran Rooney.
Mr O'Mahoney said claims made by Mr Rooney were not supported by existing members of the board.
The charity was subject to a routine audit by Irish Aid, which found it difficult to assess whether the board had the skills needed to lead a review of management proposals on development.
It found that as a result the “longer-term sustainability” of the organisation may be reduced.
The audit also claimed there was a lack of “regular comprehensive risk review” and said an internal review of the kidnap of two staff members in Sudan was not made available to the audit team.
Mr Rooney said he resigned as a result of the treatment of former Chairman Ken Fogarty, who had a row with Mr O'Shea.
In his letter of resignation, seen by RTÉ News, Mr Fogarty said Mr O'Shea behaved towards him in a manner which he said was "planned, shocking, insulting, threatening, grossly offensive and completely unnecessary".
He accused Mr O'Shea of exposing him to "unwarranted ridicule, odium and embarrassment" in front of board members.
Mr O'Mahoney told This Week that Mr O'Shea had apologised to Mr Fogarty over the issue.
Mr O'Mahoney said that he would review the salary of staff members in GOAL.
Despite financial statements published on the GOAL website which indicate two staff members are paid more than €100,000, Mr O'Mahoney insisted that was not the case.
Mr O'Mahoney said official structures had been put in place and the aid agency would be able to meet the requests of any external audit within 12 months.