The High Court has heard former Rehab boss Angela Kerins lost her job and ended up in hospital as a result of her recent appearance before the Public Accounts Committee.
The former chief executive is taking legal action against PAC alleging the spending watchdog was biased against her and acted beyond its remit.
Kerins was grilled by the Public Accounts Committee last February.
Her lawyers said questions about her €240,000 salary, her car and any bonus entitlements were pursued in a hostile manner, rather like a witch hunt.
They claim the committee went well beyond its remit and showed bias against Angela Kerins who fell ill and lost her job as a consequence of her appearance before PAC.
Her solicitor, Aidan Eames, read a statement on her behalf outside the court.
"I have attempted thorough my legal advisors to avoid the legal impasse that has occurred and the unfair treatment I suffered at the Public Accounts committee," it said.
"Regretfully, the PAC continues to attempt to conduct an unfair, unlawful, and prejudicial investigation against me.
"I have had no alternative but to apply to the courts for protection of my rights as a private citizen."
The former Rehab boss wants damages, declarations PAC used unfair procedures and orders restraining the committee from making any findings about her role or salary in Rehab.
The case comes back to court in November.