The Moderator of the Presbyterian Church in Ireland, Rev Trevor Gribben, has stepped down over alleged safeguarding failings that placed people "at risk".
Rev Gribben will leave his position at the end of the month over failings that occurred between 2009 and 2022, it was announced on Wednesday.
"Following an internal investigation and report, it has become clear that there have been serious and significant failings in the central safeguarding functions of the Presbyterian Church in Ireland," he said.
"As a result of this, people have been placed at risk. We are aware of a number of people who have been harmed, and we believe there may well be others as yet unknown to us. We apologise unreservedly for this."
He added: "The Church's first and greatest concern about this is for those people who have suffered harm, and those who have been put at risk.
"The Presbyterian Church in Ireland profoundly regrets this, is deeply grieved, and will offer all possible support to those affected."
Rev Gribben was installed as Moderator in June. He also holds the position of Clerk of the Assembly and General Secretary, which he confirmed he will also be relinquishing.
"I have made these decisions and taken these steps with the deepest personal regret that our central failings have caused such harm to those who deserve our protection the most," he said.
Rev David Bruce, Convener of the Church's General Council, said the Church's Safeguarding Team had "identified a number of situations between 2009 and 2021, with one as late as 2022, where we have failed to deliver an adequate safeguarding service".
These included, he said, inadequate responses to concerns brought to them about individuals in congregations, but also failures to involve statutory authorities when necessary.
"These failings were magnified by major gaps in necessary record keeping, so it is inevitable that we have not identified all situations where practice was unacceptable," he said.
The acting Clerk of the General Assembly, Rev Dr David Allen, said the Police Service of Northern Ireland (PSNI) are investigating one individual but that there are three Presbyterian congregations on both sides of the Irish border "where we are aware of people who have come forward and spoken with us".
