If you are flying into Haikou from the west, you can see it. Sit on the right-hand side of the aircraft and look out of your window. It's there. Viewed from above, this vast swathe of land may not look like much – fuzzy green vegetation, shadowy pockets of volcanic rock, incongruous veins of reddish brown soil – but in a couple of years it will make history. Locals refer to this area by its code name: Project 791. Soon, most people will know it as Mission Hills Hainan, the largest collection of golf courses in the world.

The scope of the multi-billion-dollar project is staggering. It occupies 80sq km of forest and shrubland – an area the size of Hong Kong island – in north-east Hainan, the island province long touted as China's answer to Hawaii. Once completed, it will feature 22 golf courses, at a stroke doubling the number on Hainan today. It's been in the works since 2006 and for more than two years, thousands of workers have been clearing trees, moving soil, building greens, fairways, clubhouses and luxury hotels.

And yet aspects of the project remain as mysterious as the island on which it sits. In fact, the man most closely connected to the Mission Hills venture in Hainan denies its very existence.

When I first met Ken Chu, vice-chairman of Mission Hills Group and one of the most powerful men in China's burgeoning golf industry, I was wearing yellow plastic bags over my shoes. Our interview was to take place in an $11m villa, one of the many that line the fairways at Mission Hills Golf Club in Shenzhen, the Chinese business hub north of Hong Kong. I was told that everyone who entered the show home must don the protective shoe coverings. Shuffling past a white grand piano I took a seat in a living room whose styling might best be described as neo-Liberace. When Chu arrived, the first thing I noticed was his shoes – stylish, black, leather and uncovered. I stood up to greet the 35-year-old mogul and cheap plastic crackled beneath my feet.

For now, Mission Hills Shenzhen touts itself as the “World's No. 1”, and Guinness World Records plays along, labelling the 20sq km, 12-course golf club the largest on the planet, even though Nanshan International Golf Club in north-eastern China has 63 more holes. Opened in 1994 by Chu's billionaire father, Hong Kong businessman David Chu, this is golf on steroids. Each of the 12 courses was designed by one of the biggest names in the sport, from Faldo to Nicklaus to Norman. Mission Hills Shenzhen also features the world's largest clubhouse, Asia's largest spa and, for good measure, the continent's largest tennis centre.

Towards the end of our meeting, I brought up Hainan. I asked Chu how many courses Mission Hills had planned there. It was the first time I saw him flustered. “We, um, it's not so much on the course development,” he stumbled. “Actually, we haven't even started. We haven't even talked about this project. It's something in the pipeline, in discussion, but it's not purely on golf. It's a tourist destination.”

“So, it's just too early to say anything?” I asked. “Maybe at this stage,” Chu said, “because there's nothing to talk about.”

This was in July last year. When I travelled to Hainan in August, I discovered that not only was there something worth talking about, but a large part of the project was nearing completion. Six golf courses had been shaped and seeded. Three more – including the showpiece “tournament course” – were even further along. They looked perfectly playable, lush and green, with local women in rattan hats the shape of Tiffany lampshades putting the finishing touches to the white-sand bunkers.