UK supermarkets are increasingly rounding up prices to the nearest pound or 50 pence, a study from price comparison website has found.

The study examined prices at the UK's largest retailers, including Tesco, Asda, Sainsbury's. It found that shoppers are paying a penny more on thousands of items.

Asda's free-range extra large eggs have increased in price from GBP1.99 (US$3.21) to GBP2, Sainsbury's has upped the price of tuna pate from GBP0.99 to GBP1 and Tesco has raised the price of a 390g pizza from GBP1.49 to GBP1.50, the study highlighted.

A spokesperson for Sainsbury's denied that the company had a policy of rounding prices up, while Asda insisted that its pricing policy was to be cheaper than the other supermarkets.

Tesco said that it had started offering GBP1 products to make pricing more "transparent".