According to reports online Apple's tiny iPod shuffle is emerging as the company's biggest-seling music player.

Shoppers are so smitten with the company's new MP3 player, which costs £55, that stores online and offline are fast running out.

Both Play.com and Amazon.co.uk are out of stock with Amazon.co.uk who has promoted the MP3 player hard on its site has not only run out of stock, appearing to have been unable to fulfill orders. In a statement on the Shuffle's product page the company says:

"We are currently waiting for information from the supplier on when stock of iPod shuffle will be available. We are working hard to get stock for customers who have already pre-ordered the Shuffle. Please click the "sign up" button above to be notified when this item is available for order."

Amazon in the US is also listing the product out of stock with the following statement:

"In stock soon. Order now to get in line. First come, first served."

It appears Apple executives are "thrilled" at the strong sales, which appear to be hitting 5 million units this quarter. Demand is overtaking supply, according to AppleInsider.

The Apple store in the UK is listing the player, but with a 5 day shipping wait. In contrast its most popular product - the iPod nano (Product) RED Special Edition is shipping within 24 hours.