Auckland Council put $175,000 of ratepayers' money towards the ASB Classic tennis event this year.
The Auckland Ratepayers' Alliance says this is "an outrageous use of ratepayers' money", but the council's Auckland Tourism, Events and Economic Development (Ateed) says it is a worthwhile investment for an event that injects more than $2 million into the domestic economy.
Ateed has invested in the ASB Classic every year since 2011, and has provided $175,000 this year as well as in 2016, 2017 and 2018.
Auckland Ratepayers' Alliance spokeswoman Jo Holmes said it was an "outrageous use of ratepayers' money".
"The ASB Classic has been hugely successful in recent years, with plenty of media coverage. Why can't the large profitable bank with its name on the event pay for the event? Auckland Ratepayers are being ripped off."
Holmes said if the event was so successful and brought so much economic activity to Auckland, "why does it need any financial help from Auckland ratepayers? Next year the ASB Classic should stand on its own two feet".
The figure for the 2019 funding is revealed in a response from Auckland Council to a Local Government Official Information and Meetings Act request from the Taxpayers' Union.
Ateed head of major events Stuart Turner said that the investment aimed to deliver economic and social benefits for Auckland.
"This includes spending by visitors who come to Auckland for events, bringing new money into our region, and showcasing Auckland to international and domestic audiences through broadcast and other media channels."
He said in 2018, the major events portfolio delivered an estimated $76 million into the regional economy and generated more than 405,000 visitor nights.
"The 2018 tournament attracted 4830 visitors, generating 13,220 visitor nights with a total tourism expenditure of more than $2 million, and we're expecting another strong result for the just completed event," Turner said.
Taxpayers' Union executive director Jordan Williams said local government agencies regularly spend money on events "of questionable value".
"In our opinion, ratepayers deserve better than that."
But Turner said the ASB Classic also promoted Auckland as a destination via broadcast channels into key visitor markets, as well as through the social media channels of high profile players.
"Coverage of the 2018 event reached more than 88 million households in 11 international markets.
"We also work to encourage international and domestic visitors who come for the event to get out and explore what's on offer in Auckland off the court as well."
He added that Ateed's funding model changed in 2017 so that half of its destination budget comes from the accommodation sector, significantly reducing the reliance on residential ratepayer funding.
ASB tennis events this summer was billed as one of the most exciting in its history, featuring the Williams sisters, Caroline Wozniacki and Ana Ivanovic in the women's event and the three previous men's champions Roberto Bautista-Agut, David Ferrer and John Isner.
The men's event finished this weekend, with American Tennys Sandgren defeating hometown favourite Cameron Norrie 6-4 6-2 in the final.
German Julia Goerges created history at the women's event, becoming the first woman to win back-to-back titles in 15 years, defeating Canadian Bianca Andreescu in the final.
This summer Ateed has invested in a mixture of events including the Wonder Garden Festival, Splore, the Hockey Pro League and the Auckland Lantern and Pasifika festivals.
• $175,000 Investment in ASB Classic event by Auckland Council agency Ateed
• 4830 Visitors at the tournament
• $2 million + Spending in the Auckland tourism sector from the event