Two TDs will give evidence when the Disclosures Tribunal returns next month to examine the alleged senior garda smear campaign against Sergeant Maurice McCabe.
Fianna Fáil's John McGuinness will be questioned about his claim that former garda commissioner Martin Callinan told him that the whistleblower sergeant abused his own children.
Mr Callinan denies saying this.
Fine Gael deputy John Deasy is also scheduled to give evidence.
Comptroller and Auditor General Seamus McCarthy will be asked about his exchange with Mr Callinan.
Also listed are the former head of the Road Safety Authority, Noel Brett, and solicitor Gerard Kean, along with Andrew McLindon, head of garda communications.
The tribunal returns on 9 April.
Its first week will examine a meeting between Mr McGuinness and Mr Callinan on 24 January 2014 at Newlands Cross in Dublin.