It took a month after the initial request for the Taoiseach's office to receive a briefing about what he thought was a videocall with African diplomats, but turned out to be Russian comedians.
Footage of the incident, which occurred on October 4th, 2023, was released by the Russian duo in December.
Vovan and Lexus, noted for their prank calls to high-profile people, previously targeted a number of prime ministers and senior political figures in Europe, as well as celebrities.
Afterwards, Taoiseach Leo Varadkar said he was “immediately suspicious” but “played along”, giving “careful answers” before ending the call.
He also cautioned “it is not as it appears” on their video, saying artificial intelligence was used.
“There were no Russians, they used an AI image of somebody who works with the African Union,” he said.
Internal messages, seen by BreakingNews.ie following a Freedom of Information request, show a briefing was first requested on September 3rd, but was not sent until the afternoon of October 2nd, two days before the videocall took place.
The initial request, purporting to be on behalf of African Commission chairman H.E. Moussa Faki Mahamat arrived on September 1st.
On September 3rd, an official in the Taoiseach's office said she believed Mr Varadkar should do the call, but requested a follow up from the Department of Foreign Affairs.
The Taoiseach's private secretary, liaising with a man who called himself Tordeta, offered a date for the videocall on September 11th. Tordeta agreed to the meeting on Monday, September 25th, at 11.30am.
An email on September 11th, sent to an official in the international division of the Department of the Taoiseach, asked: "Did you have a chance to check re the African Union call?"
On September 18th, the Taoiseach's private secretary said Mr Varadkar was no longer available for the proposed date of September 25th.
The following day, September 19th, an email from an official in the Taoiseach's office to the international division read: "Hi, just checking a request has been sent to DFA about this? We asked for advice, so they know this is in the offing."
On September 25th, the Taoiseach's secretary re-scheduled the videocall for October 4th at 3.45pm.
The next day, September 26th, another reminder was sent to the international division requesting a briefing.
The email included the new date for the videocall, adding: "I would be grateful if you could provide briefing for this occasion and for an official to attend please."
The briefing material eventually arrived on Monday, October 2nd.
Correspondence after the hoax came to light in December concerned the fallout of the incident and responses to media requests from the Taoiseach's office.
The two pranksters, real names Vladimir Kuznetsov and Alexei Stolyarov, published the call on right-wing video website Rumble, bringing up topics including the invasion of Ukraine, Irish unification and neutrality.
