Grace was left in the care of a foster family in the South-East for 20 years despite physical abuse, neglect and possible sexual abuse.
In April, the High Court approved a €6.3m settlement for Grace and described her treatment as a scandal.
The chief executive of Tusla, Fred McBride, appeared before the joint committee on children and youth affairs yesterday to discuss foster care services.
During the meeting, Sinn Féin TD Kathleen Funchion asked if staff involved in the Grace case were still employed by Tusla.
Mr McBride said he was not going to say much about the case because it was the subject of a commission of investigation.
Over the last year or so, he spent a long time trying to identify the staff involved in the case to discover whether or not they still worked for Tusla and whether they agency needed to do anything about it.
He said it was “only relatively recently” that the agency had managed to identify those involved.
“I worked hard to identify who the staff were and where they were, and for those staff that we identified as still being employees of Tusla, we put appropriate human resources processes in place.”
Ms Funchion pressed Mr McBride to say if some of them were still employed by Tusla. He replied: “Some of them are.”
Ms Funchion said she was surprised to hear that.
She thought a lot of people would be very shocked to hear that individuals involved in that “horrific” case at any level would still be employed by Tusla.
Tusla chief operations officer, Jim Gibson, said they had done absolutely everything within a legal framework to address the issue. He said the staff involved in the Grace case, which went back a significant number of years, were facing a robust inquiry process.
“They have a right to fair procedure and to put their case forward,” he said.
It would be “ridiculous” for them to comment on the case. “We have adopted a position that is grounded in legal advice,” he said.
Mr Gibson also pointed out that the committee chair had made it clear to them before the meeting that the matter was not up for discussion.
Earlier, Mr McBride said media coverage of cases was especially challenging for Tusla because of the need to maintain confidentiality.
He believed they needed to stop simply saying that they did not comment on individual cases because it was not particularly helpful to the media or politicians.
While they could not comment on the detail of individual cases, they could mention the circumstances children find themselves in and the decisions made.
There were 6,308 children and young people in foster care services at the end of March, of which 5,819 (92%) were with both general and relative carers in family settings.
Mr McBride said he “absolutely accepted” there was still structural weakness in the agency — an organisation of more than 4,000 people established in January 2014. “There are some structural changes we need to make after three years. There is no doubt about that,” he said, pointing out that interagency communication remained a challenge.