Speaking to the Mail on Sunday, James - whose own business has had to fight off Amazon’s dominance in the electrical goods market, asked: "Why is Amazon getting into the food market?"
He added: "Does it really think it can make money by selling food online? Definitely not. It’s all about how it can get its customers more and more addicted to Amazon Prime and the rest of the Amazon story.
"Amazon doesn’t want to make money out of food, whereas everybody else does and that could make it a threat for big supermarkets."
James told the Mail that rumours that Amazon might acquire online supermarket Ocado were telling.
"The question is, can Amazon get to significant scale in the food market and can it do so without making a big move?" he said.
"If it were to acquire Ocado, suddenly it would have unlimited capital, unlimited market-ing budget and a fantastic brand. That could be quite uncomfortable for existing players."
The Dixons Carphone boss, who oversees retail brands Dixons PC World and Carphone Warehouse, has been widely lauded for his success in keeping the bricks-and-mortar (and online) retail group thriving in a marketplace increasingly dominated by online players.