A new Department of Foreign Affairs report says there was a "serious breach" of Covid restrictions at a champagne party in June 2020.
Simon Coveney requested the report after a photo of the indoor event was posted to social media.
The party was attended by department officials who were celebrating Ireland's securing of a UN seat.
Covid restrictions at the time limited gatherings to six people from other households, which was violated.
The image was posted on Twitter by the then secretary-general Niall Burgess, and later deleted.
Current Secretary-General Joe Hackett was over the review.
The report found that while rules were breached, the gathering was not organised.
Group photo
The report found that Mr Burgess "was largely responsible for facilitating the breach of social distance guidance that occurred" by providing alcohol and organising a group photo.
"He also placed colleagues, particularly more junior ones, in a difficult position. His actions were uncharacteristic errors of judgement. He sincerely regrets this.
"He has provided outstanding public service throughout his career, including a leading role in supporting peace and reconciliation on this island."
Mr Hackett concluded: "This may have been a brief lapse, but has understandably raised public concern. It has also damaged the reputation of the Department.
"Accordingly, I have asked the former Secretary General to make a donation to a charity providing assistance to people affected by Covid in the amount of €2,000 and the three other senior officials to make a similar donation in the amount of €1,000.
"Each of the officials concerned has agreed to do so. I do not intend to take any further action."
The secretary general of the Department of Foreign Affairs delivered the report to Minister Coveney on Monday morning.
Mr Hackett also apologised to the public, saying: “It was a mistake. It should not have happened and, on behalf the Department, I would like to say sorry.”
He said it had “caused offence to the public who were unable to come together at significant moments in their professional and personal lives.”
“At that time, many of our fellow citizens were dealing with the devastating impact of the pandemic and grieving the loss of loved ones” he added.
In a statement, Mr Coveney said: “I believe the report is a fair and balanced account into the events which occurred on 17 June 2020.
“I note the conclusions and welcome the actions being taken by the Secretary General.”
Mr Coveney has previously said he would be happy to answer questions on the matter at the Oireachtas committee on foreign affairs if requested. - Additional reporting from Press Association
