The flagship supermarket in Kensington was widely expected to throw open its doors in March this year - and the company had previously confirmed publicly it would open in the spring.
It has now announced the outlet will not commence trading until June, though it declined to comment further.
One industry insider claimed the retailer was experiencing difficulties with Kensington and Chelsea Borough Council regarding how it was proposing to take delivery of stock. "Whole Foods Market wanted to get its suppliers to deliver directly to the store and the council had an problem with the number of deliveries, as it is quite a residential area," he said.
Another expert said it was also possible the £3bn-turnover US company was struggling to secure supplies of organic produce in the UK because the multiples had got in there first. "The supermarkets are looking for areas of profit and growth, and are focusing on organic and fair trade," said Tim Kershaw, director of supply chain consultancy Libra Europe.
"Unless Whole Foods Market has developed a good relationship with them, the attraction for suppliers is always going to be volume, and that's what they are getting from the supermarkets."
Meanwhile, Whole Foods Market is continuing its recruitment drive ahead of the opening. It is searching for a logistical operations team leader and an array of shopfloor staff to work at the Kensington store, which will eventually boast a wine bar, classy restaurant and pub selling organic beer.
Cookery demonstrations and product samplings will take place.
Last November, Whole Foods Market was named in The Grocer as the World's Greatest Retailer for the second year running.