Saudi Arabia is expected to make an offer of up to £150 million (NZ$290 million) to host the fight between Anthony Joshua and Tyson Fury.
The pair could also share about £95 million (NZ$183.6 million) in pay-per-view fees in a potential split with four major broadcasters as part of the biggest deal in British boxing history.
Saudi Arabia's main challengers are Shanghai and Singapore as promoters race to find a site after two-fight contracts to unify the world heavyweight titles were signed.
Logistical headaches of hiring and selling tickets for a 90,000 venue during the pandemic has all but ended hopes of the first fight taking place in London or Las Vegas.
An offer from Saudi Arabia is already the front-runner, with analysts predicting a deal at least double the £70 million (NZ$135.3 million) fee it paid for Joshua's rematch against Andy Ruiz Jr.
The potential choice of Saudi Arabia has worried human rights campaigners, who claim abuses extend beyond the murder of Washington Post journalist Jamal Khashoggi.
Kate Allen, director of Amnesty International UK, said: "It will come as no surprise to see Saudi authorities once again using a major sporting event as a means to sportswash its atrocious human rights record."
As far as the promoters are concerned, Saudi Arabia – where Covid-19 rates are comparatively low – is the fastest and easiest place to getting the fight done. The state's leaders are keen to enhance their status on the global stage.
An offer of up to £150 million from Saudi Arabia for a fight in June or July would be just the start for the two British heavyweights. The contract would have the fighters getting a 50-50 split in the first bout and a 60-40 split in the rematch in favour of the winner.
While 90,000-plus fans at Wembley would be an obvious choice for the rematch, the unpredictable weather in October might prompt the promoters to consider Cardiff and its retractable roof. Los Angeles or Las Vegas will also be considered.
Four broadcasters – ESPN, DAZN, BT Sport Box Office and Sky Sports Box Office – are likely to share coverage on pay-per-view.
Fury, 32, is the World Boxing Council champion while Joshua, 31, holds the World Boxing Association, World Boxing Organisation and International Boxing Federation titles.
Both parties say the location must be agreed upon within 30 days or the deal is off.