In its Infrarouge programme, RTS said the figure of CHF 1.98 billion is the operational budget and does not include costs for bidding, infrastructure and public security during the Games.

Swissinfo reports the additional amount can be broken down into CHF 25 million (£19 million/$25 million/€21 million) for the candidacy, CHF 100 million (£76 million/$101 million/€86 million) for infrastructure and CHF 300 million (£229 million/$303 million/€257 million) for public security.

RTS said the revised total had been confirmed by Sion 2026's financial director, Pierre-Alain Cardinaux. 

Sion 2026 vice-president Bernard Rüeger admitted there had thus far been a lack of communication regarding the budget for the Games.

"From now on we need to be more transparent," he told RTS.

Rüeger also said the cost of constructing an Olympic Village is not included in the budget.

Made up of some 1,400 apartments, the Village would be financed privately.

Rüeger said Sion 2026 would be happy to rent the infrastructure for this.

According to a feasibility study seen by RTS, it is estimated that 2,500 police officers per day would be required across a three-month period.

The study also concluded that security costs are likely to increase, as was the case for the 2010 Winter Olympics in Canadian city Vancouver.

Last week, Sion's bid for the 2026 Winter Olympic and Paralympic Games was given a significant boost after Switzerland's Federal Council confirmed their support for the project.

The Federal Council warned, however, that the bid will not proceed without public support.

The declaration of support was announced following a meeting on October 18 that, in principle, the Government would back the city's attempt to secure the hosting rights for the event to the tune of about CHF1 billion (£764 million/$1 billion/€855 million).

It now has to go through the two Parliament Chambers between now and December 2019 for final approval.

The backing is also dependent on the condition that the Games would rely as much as possible on existing infrastructure.

Under the proposed Sion 2026 bid, only two new venues are expected to be required to stage the Games, although existing sites could be adapted.

Sion's bid is still likely to face a referendum, which will decide whether it will go forward to the next stage.

Several venues would be used in the city of Sion, located in the canton of Valais, but a total of five cantons of Switzerland feature in the proposed plans.

It is not yet known whether referendums would be held in each.

Referendums have ended several European attempts in recent years following growing apathy towards bidding for the Olympic Games.

Innsbruck in Austria became the latest city to suffer a referendum defeat earlier this month, killing their bid for the 2026 event.

insidethegames has contacted Swiss Olympic for comment.