The Public Expenditure Minister Brendan Howlin says the former head of the Central Remedial Clinic could be compelled to appear before an Oireachtas Committee.
Brian Conlon resigned yesterday over the top-ups controversy which saw charitable funds used to boost executive salaries.
He said he would not be answering questions at the PAC when it meets this week.
Minister Howlin said Mr Conlon should volunteer himself to appear before the Public Accounts Committee and he said the committee has the power to force Conlon to appear if necessary.
But it is unclear if the new powers of compellability will work as the CRC is not a public body and Mr Conlon was never a public servant.
"He should attend that committee nonetheless," said member of PAC, Sinn Fén's Mary Lou McDonald. "I suppose now, we [will] have to look at getting the powers … to force the hand of [these individuals]."