An estimated $12 million will be needed to cover the costs of looking after heads of state visiting New Zealand for the 2011 Rugby World Cup.
Ministerial Services, within Internal Affairs, had secured the $12m for the extra costs, the department's chief executive Brendan Boyle told a Parliamentary committee today.
Ministerial Services were working with the Ministry of Economic Development and Foreign Affairs to work out exactly what would be required.
Speaking to media, Mr Boyle said it was hard to predict demand but the service had done some work based on its picks of which countries reached the finals.
About 70,000 visitors were expected here for the event and "obviously there's going to be a proportion of those that are heads of state and other guests", he said.
"We've made some assumptions for planning purposes and...a lot of that depends on us making assumptions about where teams get at certain parts of the tournament."
The service was also looking at previous events such as Royal family members visiting during the Lions tour.
"We've been able to base some assumptions about who we thought might be coming and how many people they might be just based on previous experience.
"It's a long time since New Zealand has hosted a rugby world cup so we anticipate a lot of interest in the guests of government programme."
Leaders had not yet indicated whether they were interested in coming or not; "it's too early".
However security concerns would limit what could even be said about numbers, Mr Boyle said.
General Manager, Executive Government Support Janice Calvert told the committee diplomatic protection services would advise on what security was needed.
Other preparations underway included boosting the vehicles available to ferry dignitaries around by retaining vehicles that were to be replaced.