Under-pressure interim abuse victims' advocate Brendan McAllister was appointed to the role in August by head of the civil service David Sterling.
The appointment came amid complaints that vulnerable abuse survivors were being ignored and the recommendations of the landmark Hart inquiry, which exposed decades of institutional abuse, were not being progressed during the three-year absence of devolution.
Mr McAllister's role is to advocate for victims and examine what care they need.
A trained social worker who served with the Probation Service for more than a decade, he was head of Mediation Northern Ireland for 16 years and also worked to help address gang violence in the north-east of England.
In 2008, he was one of four people appointed as a victims' commissioner. After the end of his four-year term, he joined a mediation organisation in Brussels and later worked for the UN.
While his appointment was initially welcomed by victims' groups, some began to express serious concerns when it emerged in October that Mr McAllister was training to be a Catholic deacon, sparking fears of a potential conflict of interest.
The largest victims' group, Survivors and Victims of Institutional Abuse, later decided to disengage with Mr McAllister and have now called for his resignation over Friday's data breach. However, some other groups are continuing to meet him and support him remaining in post.
