A former treasurer of Crossmaglen Rangers GAA club has pleaded guilty to a litany of sex crimes against young boys dating back over three decades.
The GAA has apologised to his victims and his families, saying it would continue to support them.
GAA president Labhrás Mac Carthaigh praised the victims for coming forward and reporting the crimes to the authorities.
He said that while their current safe-guarding policies were "robust comprehensive in content and robust in application," the case was a "reminder to us all, if ever needed, that we can never be over vigilant in how we oversee and apply child safeguarding in our clubs".
Crossmaglen Rangers also apologised.
Ex-postman Thomas McKenna, aged 62 and formerly of Woodside Park in Bessbrook, Co Armagh, was due to go on trial next week on the first of three sets of charges he faced.
But at Belfast Crown Court on Thursday, defence counsel Kevin Magill asked for McKenna to be re-arraigned on three separate charge sheets, totaling 139 sexual offences.
McKenna, who was produced to the court from Maghaberry Prison, pleaded guilty to a catalogue of offences which included indecent assaults, sexual assaults and gross indecency on young males on dates between 1989 and 2018.
A number of charges, including attempted rape, were left on the court books and not be proceeded with without the leave of the Crown Court or the Court of Appeal.
In June 2021, McKenna pleaded guilty to 18 counts of voyeurism, four indecent assaults and one count of taking an indecent image of a child.
The former postman was placed on the sex offenders' register as a result of the guilty pleas.
Following his guilty pleas, Belfast Recorder Judge Patricia Smyth said: "Stand up Mr McKenna. By your pleas of guilty you have admitted a catalogue of terrible offences against vulnerable young men.
"You will be punished severely for that.
"I am aware that some of those affected may be on the [video] link. To those affected may I say this: 'I praise your courage in coming forward to disclose these terrible crimes in very, very difficult circumstances'.
"Today each of you is completely vindicated in the complaints that you made against this man. I hope that that vindication will bring some peace of mind to those of you who continue to suffer grievously.
"And may I also say this: 'By coming forward and being determined to see this process through to its conclusion, you have brought about this situation where this man has admitted his guilt.
"Each of you have done a great public service in coming forward and I want to thank you for that,'' added Judge Smyth.
Prosecution counsel Charles MacCreanor KC said the Crown would not be proceeding with a number of matters which had recently come to light and the defendant had signed a document that these matters would now be "taken into consideration'' along with his guilty pleas.
Defence counsel Greg Berry KC asked for a pre-sentence report to be prepared on McKenna by the Probations Service NI ahead of sentencing.
He added that he would also be seeking a medical report to be completed on McKenna which he said "related to a number of issues''.
The case will be reviewed on Monday 7 November.
In a statement, GAA president Labhrás Mac Carthaigh said: "I am aware that a former Treasurer and member of Crossmaglen Rangers CLG, Mr Thomas McKenna, appeared in court today, 29 September 2022, and pleaded guilty to numerous charges of sexual abuse that span over a 30-year period.
"On my own behalf and on behalf of the GAA I wish to apologise to his many victims in Crossmaglen Rangers, and to their families, for the hurt that has been caused by this abuse and to assure them that the GAA will continue to support them on an on-going basis."
He continued: "Our current child safeguarding policies are seen by many to be comprehensive in content and robust in application and while much of the abuse perpetrated by Mr McKenna goes back almost 30 years, it is a reminder to us all, if ever needed, that we can never be over vigilant in how we oversee and apply child safeguarding in our clubs. "I want to acknowledge and express my admiration to the victims for the courage they have shown in coming forward and cooperating with our GAA safeguarding personnel in reporting the initial allegations to the statutory authorities. "I would also urge any person who may have safeguarding concerns about these terrible crimes, or other safeguarding matters in the GAA, to contact the relevant statutory authorities or the GAA at firstname.lastname@example.org or at email@example.com ."
In a statement, Crossmaglen Rangers added: "The thoughts of our Club and our community are very much with the survivors/victims and families of sexual abuse as perpetrated by Mr McKenna, and we wish to respect their privacy and that of their families. The GAA will continue to engage with the victims and provide support services at this time.
"Crossmaglen Rangers CLG will not issue any further statement pending the completion of the court proceedings."