The Open: Tourism NI says cost 'commercially sensitive'
The total amount of public money used to help bring The Open golf championship to Royal Portrush is not being released.
The main tourism development body in Northern Ireland, Tourism NI, said the figure is "commercially sensitive information".
Tourism NI has predicted an economic boost to the economy of more than £100m as a result of the tournament.
But no figures are available for how much money it spent.
The Department for the Economy also declined to give any detail.
A spokesperson said: "Government funding to support the hosting of The 148th Open is commercially sensitive information.
"The benefits of hosting The 148th Open will greatly outweigh the investment with regards to value for money."
However, other departments were prepared to release figures.
The Department for Infrastructure said it contributed £937,000 towards the cost of redeveloping the train station at Portrush.
The Department for Communities spent £11m on a Portrush regeneration programme. Another £6m has been earmarked for more improvements in the next three years.
The Open is expected to return to Royal Portrush within the next decade, though no date has been confirmed.
Last year, the championship was played at Carnoustie in Scotland.
The main tourism body in Scotland, Visit Scotland, has revealed it contributed £255,000.
The Open at Royal Portrush was a sell-out, with more than 230,000 spectators during the week and was won by Irishman Shane Lowry.
The Open at Royal Portrush
68years since NI hosted
£80mboost to economy
It was the first time the championship had been played at Portrush since 1951.
The local council also helped to facilitate the event.
A spokesperson for Causeway Coast and Glens Council said £350,000 was spent on The Open.
"The money was used for the following purposes: appointment of project manager; complimentary events, branding and animation; business engagement and development and the physical presentation of Portrush," said the spokesperson.
On Monday, the chief executive of Tourism NI, John McGrillen, described The Open as a 'watershed' moment for Northern Ireland.
"The fact the R&A have come here and had the confidence to bring a world class event, and the coverage that has had, will change people's perceptions of this place forever.
"This has galvanised the whole of Northern Ireland."