Editor's note February 11, 2020: An earlier version of this story said the yacht had been sold to Mr Gates. Sinot has since said that this is not the case.
Reports that Bill Gates had spent $747 million on a hydrogen-powered superyacht have been denied by the company behind the project.
Dutch-based company Sinot said there was no link between its Aqua concept yacht and the 64-year-old billionaire.
"Sinot has no business relationship with Mr Gates," it said in a statement.
"Aqua is a concept under development and has not been sold to Mr Gates."
It was earlier reported, including by the ABC, that Mr Gates was set to spend $US500 million ($747 million) on the vessel, a 112-metre long, liquid hydrogen-powered superyacht.
The design features an infinity pool, helipad and spa and would have room for up to 14 guests.
It was first revealed in Monaco in 2019 and advertised as being suitable for a "forward-looking" owner.
"For the development of Aqua we took inspiration from the lifestyle of a discerning, forward-looking owner, the fluid versatility of water and cutting-edge technology, to combine this in a superyacht with truly innovative features," marine designer Sander Sinot said at the time.
The ship is not expected to hit the open water before 2024, according to the UK's Telegraph newspaper, but has the potential to reach a speed of 17 knots and travel 6,000 kilometres before it needs to refuel.
Mr Gates was ranked the world's second-richest man in 2019, with a fortune of $US110 billion in November of that year.
He has pledged to give most of his fortune to good causes via The Bill and Melinda Gates Foundation, and recently donated $US100 million to help tackle coronavirus.
