An Oireachtas committee has heard that RTÉ has paid "over €10.4m" in defamation costs since 2010.
The letter from Vivienne Flood, Head of Public Affairs at RTÉ, to the Public Accounts Committee noted that the figure "does not take into account refunds from RTÉ insurers".
The details of the correspondence, dated 21 October, were read out by Committee chair Brian Stanley.
The Sinn Féin TD said that the committee would invite RTÉ Director General Dee Forbes to appear before it in January.
He said that Ms Forbes had declined to appear before the committee today, as she was unavailable.
The invitation was issued two-and-a-half months ago, the committee heard.
The committee was also updated on an ongoing investigation into the misclassification of "around 500" workers at RTÉ as temporary.
Sinn Féin TD Matt Carthy said it was "hard to believe" that a statement by the Revenue Commissioners accepting a €1.2m settlement from RTÉ was the only documentation available.
He agreed with the suggestion from Social Democrats co-leader Catherine Murphy to ask for all relevant documentation.
Comptroller and Auditor General Seamus McCarthy said there would be some correspondence between Revenue and RTÉ.
However, he noted that the report on which the settlement was based was carried out by [consultants] "Eversheds on behalf of RTÉ", not Revenue.
"If anybody is to release this, it has to come from RTÉ", Mr McCarthy said.
Ms Murphy said that the Eversheds report "goes back two years", but the issues go back "way longer than that", potentially affecting pension entitlements.
"Does it go beyond the Eversheds report?" she asked. "Because there could be additional Revenue liabilities."
Mr Stanley said the Department of Social Protection has already committed to look back to when the contractors in question were first hired.