The Times newspaper claimed thousands of orders had been hit by manufacturing delays and delivery problems.

But Amazon told BBC News that the only customers facing delays were some of those who ordered the hugely-popular iPod personal music systems.

Amazon said it expected to get 99% of orders delivered in time for Christmas.

Unhappy Christmas

Nonetheless, many customers of Amazon and other online retailers have been let down, thanks to a combination of late ordering, shortages of key products, and postal delays.

The worst delays have hit iPods, mainly thanks to an unprecedented surge in demand this Christmas.

Cassy Stone, from High Wycombe in Buckinghamshire, told BBC News that her iPod - ordered on 30 November - had been postponed until after Christmas.

"I have had an e-mail to tell me it wouldn't be here for Christmas but its now too late for me to get one elsewhere," she says.

"My husband has no present; my son is missing much of his present, and his friends are missing their presents!"

No worries

Speculation of supply problems caused by an unprecedented surge in online shopping have fuelled fears of a last-minute rush to the High Street.

The iPod is one of this year's most coveted gifts

But Amazon remained confident and expects this to be its most successful Christmas yet.

"We're very happy with the way Christmas has gone," said a spokeswoman for Amazon.

"We have all the plans and processes in place to deliver to customers before Christmas."

However, it advised customers to always check their accounts after they have ordered to see when their goods have been dispatched.