The Department of Justice asked for â‚¬5 million to cover the cost of security for the visit of US Vice President Joe Biden to Ireland.
The money was sought in a letter from Justice Minister Frances Fitzgerald as part of a â‚¬9.45 million bill for policing VIP visits and commemorative events this year.
It also included a plea for an extra â‚¬950,000 to cover the security costs for the short visit of Prince Charles and Camilla, Duchess of Cornwall, to Donegal in May.
The letter, released under FOI, was sent to the Department of Public Expenditure as part of a formal request from Ms Fitzgeraldâ€™s Department seeking sanction for an extra â‚¬65 million allocation for policing in 2016.
Remarkably, almost 8% of that related to the Biden visit, with the Department of Justice also told it must find savings in prisons and others services to help ease their overrun in spending.
The â‚¬5 million for the Biden visit was the same as what had been allocated to a high-profile policing operation in Dublin to tackle gangland crime earlier this year.
In the letter to party colleague Paschal Donohoe, Ms Fitzgerald wrote: â€œIn addition, extra costs will arise in the context of necessary security arrangements relating to the protection of visiting dignitaries.
â€œThe costs associated with the recent visit of HRH Prince Charles and the Duchess of Cornwall on 25 May 2016 are in the order of â‚¬0.95 million.
â€œVice-President Biden is scheduled to arrive for a 5 night visit next month and it is likely that some â‚¬5 million will be required to provide necessary security services.â€
The Department of Justice said the final bill for the Biden trip was â€œnot yet availableâ€.
Mr Bidenâ€™s six-day visit to Ireland took place in June, when he travelled here along with his brother and sister, his daughter, and five grandchildren.
As well as several days spent in Dublin, he also visited Newgrange, and the Cooley Peninsula in Co Louth where his ancestors had lived.
He also stopped off in Co Mayo where he watched Irelandâ€™s Euro 16 match against Italy in a pub in Taoiseach Enda Kennyâ€™s home town Castlebar.
Although the trip was described as deeply personal for Mr Biden, that made no difference to security arrangements which involved hundreds of gardai and Defence Forces personnel.
The extra â‚¬65 million was sought by Minister Fitzgerald in May to deal with the â€œunprecedented level of policing activitiesâ€ that were to take place this year.
However, following negotiations with the Department of Public Expenditure, that figure was reduced to â‚¬55 million.
Ms Fitzgerald explained how significant resources had already been spent trying to tackle gangland crime, particularly related to the Kinahan Hutch feud.
Ms Fitzgerald wrote: â€œIn light of recent atrocities, particularly in the Dublin inner-city area, considerable garda resources are currently being deployed to disrupt and investigate activities connected with serious organised crime gangs.â€
She said that â‚¬5 million had already been allocated for the feud but that more money â€“ the exact figure for which has been redacted from the letter â€“ was needed to keep going.
â€œThese operations, while labour intensive, are clearly having an impact â€“ both in detecting and interrupting the criminal gangs and reassuring the public,â€ she wrote.
The Minister also said she was looking for extra money (with the amount again redacted) to continue Operation Thor, a crackdown on burglary gangs particularly in rural areas.
She explained that there had been 19,000 anti-crime patrols and 23,000 targeted checkpoints, which had â€œachieved notable successâ€.
Lastly, money was also needed to keep on track programmes for increasing garda numbers, both full-time and reserve, increasing civilian staff, and investment in IT, cars and stations.
In an email between senior civil servants, the Department of Justice was told it should review its figures to try and bring them down.
It said: â€œYour Department must re-examine and pursue all opportunities to reallocate/redeploy resources from other less priority areas.â€
In the email, the Department of Justice was told it was â€œnot acceptableâ€ that with a â‚¬2.2 billion budget, there was not room to look for savings elsewhere.
â€œIt would be much better for the outcome if your Department tables a reassessment of the ask for additional Exchequer funding, which this time includes a more acceptable and realistic component of â€¦ savings,â€ it concluded.
In a summary document prepared for the Department of Public Expenditure, it was explained that ultimately a total of â‚¬55 million would be needed.
That was made up of â‚¬50.9 million in garda overtime, â‚¬2.648 million in travel and subsistence expenses, â‚¬226,000 for other expenses, and â‚¬2.139 million for operational equipment.
The Department of Justice also promised to make savings of â‚¬15.5 million through cost cutting in other areas like prisons. The document said that would bring the extra allocation needed down to â‚¬40.5 million when the savings were taken into account.
You can read the documents below: the email back to Dept of Justice and the letters from Frances Fitzgerald.