Businessman Denis O'Brien has issued legal proceedings against the Dáil's Committee on Procedure and Privileges.
The case is believed to be in relation to the Committee's finding that Independent TD Catherine Murphy did not abuse Dáil privilege when making allegations about him in the chamber.
The businessman is already taking legal action against the Houses of the Oireachtas and the State for claims made in the Dáil chamber about him.
Each member of the Committee was contacted by email on Friday to inform them that they were named in the proceedings.
The Oireachtas Committee on Procedure and Privileges is due to meet in September to discuss the issue.