The Taoiseach has said that Ryan Tubridy, his agent Noel Kelly and former RTÉ director general Dee Forbes should appear before an Oireachtas committee.
Leo Varadkar said: "We are trying to get to the bottom of what happened when it comes to these unusual, clandestine payments in RTÉ.
"RTÉ executives and board members have come before the Oireachtas committee to answer questions. But there are other people who could shine a light on this, and they include Ryan Tubridy, they include his agent, they include Dee Forbes.
"I still believe that they should be willing to come before the committee and answer questions.
"There are procedures, they will be treated fairly and I think that would be the right thing to do from their part.
"They may have a story to tell, and I think it's right that they should be allowed to tell their side of the story."
Read more:
RTÉ faces further committee questions on Tubridy's earnings
Where do matters stand in the ongoing RTÉ saga?
Kielty expresses wish to make Late Late payment public
Separately, Minister for Media Catherine Martin has said the chair of the RTÉ Board phoned her this morning to apologise for any disquiet over not informing her of the decision to ask for former director general Dee Forbes' resignation when they met last weekend.
Minister Martin said that during Saturday's meeting "we were really focused on trying to get to the bottom of the numbers, the figures behind it and thinking about that external review, that I felt is needed, and the governance issue.
"The Chair, Siún Ní Raghallaigh, did ring me this morning and explained or apologised for any disquiet caused because of that, but it was really to do with due process and individuals’ rights and I was informed as soon as the decision was taken to suspend, the suspension was put in place".
Members of the RTÉ Board and RTÉ Executive Board will appear before the PAC to face questions about understating presenter Ryan Tubridy's income.
Minister Martin said that all through this "we have to be cognisant of the good to democracy and to society of public service broadcasting, and be very aware of the staff that are impacted by this and the anger and hurt they are feeling right now and we have to build up that trust with them so we have to do our best to protect the staff, public service broadcasting, be cognisant of the value".
She said she has asked for the "greatest clarity possible" at the Public Accounts Committee, adding that she felt yesterday "there was a shocking display of governance on display in everything that was said, so we need clarity today, so I have written seeking that clarity for today."
The minister said she is in the final stages of putting together the terms of reference for the external review.
She said she also feels that Ms Ní Raghallaigh acted "so swiftly in March and is to be commended for that when this was discovered and has moved quickly, and I think that was the right thing to do."
Referring to yesterday's hearing at the Oireachtas Committee on Media, Minister Martin said she was really shocked at "what was so clear to everyone was such a broad failure of governance in an organisation that is so important to us all."
It just shows, she said , the real need to establish the trust and the real need for further clarity today.
"We must have clarity and the Taoiseach and the Tánaiste have emphasised that too. I would really appeal them [RTÉ] to bring clarity, because part of healing and rebuilding the trust is to get the answers that are needed.
"It's the governance issue, the oversight, the communication at senior management levels that seem to be lacking here, a complete failure of it and we need to see why did that happen but my job now, and I'm finalising the terms of reference, is to make sure that it never happens again."
RTÉ needs to get a grip on situation
The Tánaiste said there is a need for the RTÉ Board to get a grip on the current situation.
Micheál Martin said the national broadcaster had to ensure a sharper and very transparent presentation to the PAC, so that all outstanding questions could be answered and clarified as a matter of urgency.
Mr Martin said the matter fundamentally related to governance issues and there needed to be a look at the governance structure within RTÉ.
He said this has been damaging to morale within the RTÉ workforce and there was a lot of palpable anger.
Additional reporting Eileen Magnier, Joan O'Sullivan
