Blathnaid Ni Chof- aigh is suing RTE, the Herald has learned.
The Nationwide presenter has initiated personal injury proceedings against the national broadcaster, where she has worked in a variety of roles over the past three decades.
Ni Chofaigh (49) declined to comment on the High Court action, but it is thought to relate to grievances spanning a considerable period.
RTE previously held an internal inquiry following complaints from the presenter that she had been sexually harassed by another staff member in the 1990s.
It is understood human resources issues raised by Ni Chofaigh more recently have also been the subject of investigation.
The proceedings were initiated on Wednesday, and Ni Chofaigh is being represented by Daniel Spring and Company, a firm of solicitors specialising in employment law and personal injury matters.
It is understood a personal injuries summons has yet to be received by RTE.
Available records indicate the matter has already been considered by the Injuries Board, which exercised its discretion not to arrange for the making of an assessment of damages.
Among other reasons, this can happen in cases where there are particularly complex issues, where the injuries sustained are wholly or in part psychological or where aggravated or exemplary damages are sought.
Contacted yesterday, Ni Chofaigh said: "I can't comment, sorry."
Her legal representatives also declined to discuss the case.
A spokesperson for RTE said it did not comment on legal matters.
In a radio interview several years ago, Ni Chofaigh said she was sex- ually harassed by another staff member after she landed her first job at RTE at the age of 18.
She said this had had a devastating effect on her life.
"Sexual harassment then, nobody understood it," she said on Newstalk.
"I understood it as a feeling, what it made you feel, but I didn't have the words to articulate it.
"I didn't even understand that's what you called it, but somebody trying to undermine you by making you feel dirty and making sexual innuendo.
"That's the only definition I have of it because I've been there.
"I found myself in quite a serious situation with an internal inquiry instigated by myself because of the stuff I had gone through."
The person against whom she made the complaints is now dead.
RTE later confirmed an internal inquiry took place concerning incidents described by Ni Chofaigh.
However, it declined to reveal the outcome or the identity of the alleged perpetrator.
It is understood other work- related issues have been raised by Ni Chofaigh with RTE management in more recent times.
She joined Nationwide earlier this year as a replacement for Mary Kennedy.
Ni Chofaigh co-presented The Afternoon Show between 2003 and 2009, but left due to health problems.
The mother-of-four was a judge in The All Ireland Talent Show and took part in the reality television show Celebrity Bainisteoir.
She has also worked as an actor, featuring in the Irish language comedy Crisis Eile, in which she played Maeve Kelly Clarke, a transport minister exiled to Brussels as punishment for her many gaffes.