Sainsbury have signed a new deal with celebrity chef Jamie Oliver to continue as the front man for their forthcoming advertising campaigns.

The 12-month deal will earn the chef £1.2m compared to the £900,000 he received for his last campaign. The agreement is one of the most lucrative endorsements of recent years.

The new ads will feature Oliver acting as a ‘quality detective’ who visits the supermarket’s suppliers and buyers to test food.

Oliver said: “Working with Sainsbury’s gives me the chance to reach and inspire millions of customers with fresh new ideas on making the most of Sainsbury’s top quality foods and ingredients.

The chef’s previous campaigns are believed to have boosted sales at the supermarket by up to £1.2bn since 2000. The new deal has been completed despite Oliver’s wife being embarrassingly photographed carrying bags full of shopping from Waitrose.