The recruitment of the head of the Central Remedial Clinic (CRC) who resigned over a salary top-ups controversy is to be investigated by the Government's spending watchdog.
Beleaguered Brian Conlon, who quit the post yesterday following revelations the organisation used charitable donations to fund executive bonuses, may yet be compelled to appear before the Public Accounts Committee (PAC).
He previously refused to accept calls to be questioned.
"This recruitment was not carried out in conjunction with the HSE and, in fact, the HSE was forced to issue two performance notices to the CRC in order that it would be furnished with details of the recruitment and the proposed appointment," Mr McGuinness said.
"Contrary to public requirements, the appointment was not advertised externally and the resulting appointment was of a former board member."
Mr Conlon, who claimed yesterday that he was on holiday when the scandal emerged, had only been in the post since the summer.
He insisted his own pay was within health service guidelines and that he would not appear before PAC.
Public Expenditure Minister Brendan Howlin has since urged him to address the committee.
New laws enforced earlier this year could give the committee "compellability" powers.
However, it is unclear as to whether provisions under the Houses of the Oireachtas (Inquiries, Privileges and Procedures) Act 2013 can haul him before politicians because he was not a public servant.
In a statement yesterday, Mr Conlon insisted his successor should have no previous links with the hospital.
He resigned after revelations that public donations were being used to top up the salaries of bosses at the CRC, which treats adults and children with physical disabilities.
The CRC had been dipping into funds raised by a company called Friends and Supporters of the Central Remedial Clinic to boost pay packets of top executives.
The disclosure sparked furore among donors and relatives of those who rely on the clinic for their medical needs.
Mr Conlon said he was abroad on holidays at the time, but tendered his resignation within a day of coming home.
Despite his calls for a clean break with past leadership, Jim Nugent, chairman of the board, is standing in as chief executive on an interim basis.
Education Minister Ruairi Quinn has called for the entire board of directors at the CRC to resign.
Meanwhile, PAC chairman Mr McGuinness said the top-ups scandal at the CRC was an "issue of concern".
"Committee members will be particularly interested in examining the top-ups made to the former CEO, Paul Kiely, which were greater than the HSE funded part of his salary at 136,000 euro and the fact that five CRC members of staff are still in receipt of top-up payments," he added.
"The CRC is a registered charity. Regardless of how top-ups are funded, whether from donations or from other sources, the outcome is that there are less funds remaining to provide services to clients who require them.
"Also, when a member of the public makes a donation to an organisation, their expectation is that the donation will be spent on services for the clients who require them and not to fund additional salaries to already well paid individuals."
Elsewhere, Taoiseach Enda Kenny dismissed calls for an independent public inquiry into the top-ups controversy across hospitals and health agencies.
He said it was up to the PAC to allow the "democratic process" to work and that an inquiry would take years.
Mr Kenny said it was "scandalous" for an organisation to syphon charitable donations to excessive top-up payments.