Belfast Council spent £60,000 sending seven officials to a real estate conference in the upmarket French Riviera city of Cannes.
The four-day event in March took place in the same venue where the world-famous Cannes Film Festival is held.
The MIPIM conference bills itself as "the premier real estate event" which "gathers the most influential players from all sectors of the international property industry for four days of networking, learning and transaction".
The cost of the visit emerged after a Freedom of Information request by this newspaper.
However, the council could not quantify the financial return to the city from being present at the conference.
The event was attended by the chair and deputy chair of the council's city growth and regeneration committee, Sinn Fein's Mairead O'Donnell and Ulster Unionist Jeffrey Dudgeon.
They were accompanied by five council officers who specialise in marketing and communications, property, regeneration and economic development.
The FoI response confirmed the cost of the event to the ratepayer was £60,000.
And the bill for next year's event looks set to be even steeper.
The council plans to spend an additional £20,000 in 2019, although this was opposed by Sinn Fein.
In addition to the spend, a further £269,825 was raised from public and private sector organisations to represent Belfast at the conference.
The council's FoI response states: "The Belfast at MIPIM budget was allocated to include design and delivery of the Belfast at MIPIM stand/marketing suite and all associated marketing collateral; organisation of all events and activities at Belfast at MIPIM including the delivery of pre and post-MIPIM events and a three-day programme of events at MIPIM; purchase of delegate passes for the Belfast at MIPIM delegation and travel and accommodation costs for Belfast City Council representatives."
Approval for the attendance and spend was granted by the council's city growth and regeneration committee last year.
An October 2017 committee report said that the European event "requires a strong team presence from Belfast City Council to undertake and deliver the full suite of activities which take place at this global real estate conference".
It added that it was "seeking to raise the investment profile of the city alongside key partners", and expected the 2018 event to be "even more demanding than 2017, requiring the chair and deputy chair of committee and a team of senior officers to field the wide range of events, meetings, speaking opportunities, presentations and media engagements scheduled by the Belfast delegation working group and appointed event management company".
The council said it "does not hold" information on the estimated value of business brought back to Belfast due to the trip.
It added: "However, the Belfast agenda sets out a target of creating 1.5m square feet of Grade A office accommodation and a minimum of 3,000 new hotel bed spaces by 2021.
"Attracting investment into the city is a key mechanism required to deliver these targets.
"During MIPIM 2018, over 170 international developers, investors and occupiers attended events on the Belfast at MIPIM stand.
"In addition, Belfast City Council representatives held 18 private meetings with potential investors and key stakeholders; and attended and spoke at 35 external engagements and events hosted by investors, stakeholders and conference organisers."
The FoI response listed business leads said to have been brought back to Belfast, such as "a number of institutional investment funds including Legal & General who are actively working on funding of a number of major regeneration schemes".
The FoI request added: "Over 27,000 people attended MIPIM 2018 and it offers unrivalled access to the most influential players from all property sectors.
"Belfast attends MIPIM to showcase investment opportunities within the city and position the city as a forward-looking, dynamic and ambitious city ready for investment.
"It allows us to position the city against other UK and European cities as a place for investment and put Belfast on the radar of investors and developers who had not previously considered the city as a location for doing business."
Mr Dudgeon said the spend was "not unreasonable".
"If you don't display your wares or show yourself, no one will come near you," he claimed.
"It's always hard to be precise about the actual effect of involvement by council, but we were advised that this was a very important event."