Minister for Foreign Affairs Simon Coveney said gardaí investigated after his mobile phone was hacked in 2020.
The Minister, in a letter sent on Thursday to the Chair of the Foreign Affairs and Defence Committee Charlie Flanagan, said that his phone was “compromised” last year.
He said that his hacked phone was used to contact other European foreign ministers.
Earlier, Leo Varadkar said he will not consider resigning his position over the Katherine Zappone affair as he insisted the controversy is not “overshadowing” the work of Government.
The Tánaiste said on Thursday that both he and Mr Coveney “accept our responsibility” over their handling of the affair.
In the letter, Mr Coveney tells the committee: “Some of my foreign minister colleagues across Europe were contacted using my phone’s identity as a front during that hacking incident.
“I believe the matter was dealt with swiftly and thoroughly by my department and the gardaí from whom I take ongoing advice.”
“As a result of this incident and others, I work on the basis that very few telecommunications are completely secure,” he said.
Earlier this week, the Garda Press Office declined to say whether gardaí had investigated a hack on Mr Coveney’s phone.
What I did not know in the committee was why the Tánaiste had initiated this text conversation
In the letter, Mr Coveney denies he was trying to keep messages secret.
He said: “It was me who told the committee that the Tánaiste had raised the upcoming Zappone appointment with me by text and this has been shown to be completely consistent with what the Tánaiste’s text messages show.
“What I did not know in the committee was why the Tánaiste had initiated this text conversation.”
Mr Coveney says that he was “completely honest” with members of the committee about his interactions with Mr Varadkar.
“I accept that the Tánaiste’s text to me shows he was aware of the special envoy position in his opening question to me and that the process of appointment was near completion.”
Mr Coveney tells the committee that it is “plain wrong” to suggest he was trying to keep texts secret and rejects the idea that he misled the committee.
Speaking in Newry, Mr Varadkar said the appointment of Ms Zappone as a UN special envoy on freedom of expression “wasn’t handled in the right way”.
He said: “I don’t think it’s being overshadowed. It’s certainly a shadow, but I don’t think it’s overshadowing what is a really important day for the Government, for the country.”
Former agriculture minister Barry Cowen said his own sacking, related to a historic drink-driving offence, had happened because it was distracting the work of Government, and he suggested the Zappone controversy is doing the same.
Mr Cowen said: “I was told that this issue was dominating the public domain and was getting in the way of Government business. Some would argue this is getting in the way of Government business too.”
On Ms Zappone’s appointment, Mr Varadkar said: “It wasn’t handled in the right way. Unlike other special envoys, it was politically sensitive because she was a former Cabinet member.
“There was a responsibility on Simon or me, or both of us, to inform the Taoiseach and Minister (Eamon) Ryan in advance. We didn’t do that. That’s essentially what happened, and we need to ensure that doesn’t happen again.”
The Tánaiste denied that it reflected badly on the Minister for Foreign Affairs that while he himself has released text messages related to the appointment, Mr Coveney had deleted his, saying he had done so because his phone was hacked.
Mr Varadkar said: “The difficulty is I suppose, Simon, when he was making his account to the committee, had deleted the texts.
“I still had them, so I was able to jog my memory and remember what had happened or not. But bear in mind this is an appointment that did not proceed.”
The Tánaiste said there would not be sanctions for the freedom of information (FOI) officer who failed to release the text messages when requested by journalists.
He said: “Because I was away and my senior staff were away, I wasn’t asked whether I had any messages on my phone.
“That’s what happened, an honest oversight. I don’t think there will be any consequences for the official involved. It would be very unfair.”
He said procedures will be put in place to avoid a repeat of the situation, but he added this could mean “delays” to the FOI process.
Meanwhile Fine Gael minsters have been defending Mr Varadkar and Mr Coveney over the controversy.
Simon Harris has rejected suggestions that they should consider resigning.
Junior minister Hildegarde Naughton denied it was overshadowing the work of Government.
On Wednesday, Taoiseach Micheál Martin said any records related to Government business are “normally retained”.
On Wednesday, Mr Varadkar released a series of text messages exchanged between himself, Mr Coveney and Ms Zappone ahead of the party.
The texts reveal conversations about Ms Zappone’s controversial appointment as a UN special envoy, a role which she later relinquished.
The exchange shows Mr Varadkar was asked by Ms Zappone about her appointment 11 days before Cabinet met to approve her for the role.
It also emerged that Mr Varadkar and Ms Zappone discussed the role during the Merrion Hotel event in July.
On Thursday Mr Varadkar said the first he had heard of the Zappone appointment was in a text from Mr Coveney on July 19th.
Mr Cowen said members of his party are beginning to feel that Fine Gael ministers are being treated more favourably than previous Fianna Fáil ministers who had endured similar controversies.
Asked about the reaction of Mr Martin to the row, Mr Cowen said: “The Taoiseach acknowledged the text and information contained therein relating to Government business should not be deleted, but doesn’t allude to the fact about the startling information that’s contained within those texts.”