It is a match some have dubbed the clash of titans.
Businessman Oei Hong Leong is suing Canadian real estate giant Concord Pacific Group - a firm originally founded by Hong Kong tycoon Li Ka Shing but now run by Mr Terry Hui, whose family bought Mr Li's controlling stake in the 1990s.
Mr Oei filed a civil claim on Monday in the Supreme Court of British Columbia, alleging that Concord abused the court process and interfered with his rights to develop a plum site in downtown Vancouver with other parties.
Concord had filed a civil claim in January, alleging that it had an agreement with Mr Oei and his companies to jointly develop the plot.
Mr Oei said this claim is false.
The property at the centre of the dispute is the Plaza of Nations, a 550,000 sq ft site Concord has valued at about C$500 million (S$522 million). It was the heart of the 1986 Expo World Fair in the city.
Mr Oei bought the property from a Concord affiliate in 1989. It is part of a larger site - also used for the Expo - that Concord bought from the province of British Columbia in the mid-1980s. Concord developed the larger Expo site into a project of more than 50 buildings, known as Concord Pacific Place.
In 2012, Mr Oei's company filed a re-zoning application for a massive mixed-use development for the Plaza of Nations plot - including 1,700 to 2,000 homes, retail and office space, a hotel, a community centre as well as an ice rink and sports science centre.
Concord's claim alleges that Mr Oei had agreed last year to enter into a joint venture for the redevelopment of the site, and that Concord was to acquire a 50 per cent indirect interest in the property.
The agreement was made partly in writing and partly verbally. Concord allegedly paid Mr Oei an initial deposit of C$10 million.
Under the terms of the alleged agreement, Concord would, among other things, provide development, construction, marketing and sales and leasing management services, it said. It is suing Mr Oei for breach of the agreement, and is seeking an order that the deal either be carried out or that the deposit be returned with interest along with other damages and costs.
But in Monday's claim, Mr Oei denied there was ever an agreement.
He also claimed that Concord, knowing that its claims were not true, tried to prevent him and his company from developing the property in partnership with other Canadian parties.
Mr Oei, who is claiming damages and costs, has also alleged that Mr Hui, who is Concord's president and chief executive, and Concord wanted to induce or compel him and his company to continue negotiations with Concord.