Jamie Oliver has come under fire for using his fans to act as field marketers in Sainsbury's supermarkets.

Through the celebrity chef's website, his staff recruited fans as mystery shoppers to check displays of his Italian range. They were urged to take photos of in-store displays of pasta sauces and oils - and promised a free peeler in return.

Oliver's followers responded by posting pictures of the displays on the site. But some users of the website hit out at the multi-millionaire.

One, writing under the name dcc251, fumed: "I know this is done by all companies. It is, however, done by paid professionals, who are expected to be objective and file reports evaluating the overall marketing impact of a product.

"Sainsbury's is paying a mint to Jamie Oliver for their name on this product and in their own marketing."

Sainsbury's said in a statement: "Jamie's Italian range is displayed very well in-store, but we welcome all customer feedback."