The cost of some everyday groceries has more than doubled over the last year, consumer brand Which? has found.

The company analysed inflation on more than 25,000 food and drink products at eight major supermarkets – Aldi, Asda, Lidl, Morrisons, Ocado, Sainsbury’s, Tesco and Waitrose.

Which? looked at the average price of the products in the three months to the end of February 2023 compared to the same time period last year.

Data revealed that prices increased most at Lidl, followed by Aldi, Asda, Morrisons, Waitrose, Sainsbury’s, Tesco and then Ocado.

Which? found a range of everyday items – including milk, meat and fruit – on each supermarket’s list of groceries with the highest inflation.

The company said own-brand products were particularly hard-hit and also featured heavily on lists.

The findings showed that budget and own-brand items were subject to higher rates of inflation than premium and branded counterparts overall.

Annual inflation of popular food and drink was found to be at 16.5% across the eight retailers in February. In particular, inflation on vegetables, juice drinks, smoothies and cereal rose.

According to the consumer brand’s food and drink inflation data, the average price for Asda’s Free From Special Flakes (300g) increased by 129%, rising from 62p to £1.43.

Meanwhile Waitrose’s Essential Italian Mozzarella Strength 1 (drained 150g) rose from 80p to £1.77, a 121% increase.

Morrison’s Free From Corn Flakes (300g) also rose significantly from 60p to £1.29 (115%).

Sainsbury’s Hubbard’s Foodstore Water (2L), Tesco Creamfields French Brie (200g) and Lidl’s Chene D’argent Camembert (250g) also more than doubled in price.

Sue Davies, Which? head of food policy, said: “Worryingly our tracker shows that some everyday essentials have more than doubled in price over the last year – with cheaper own-brand items particularly hard hit.

“Supermarkets need to step up and ensure everyone has easy access to basic, affordable food ranges at a store near them, particularly in areas where people are most in need.

“Retailers must also provide transparent pricing so people can easily work out which products offer the best value.”

A Lidl spokesperson said: “We are extremely concerned that since the launch of this ‘tracker’ Which? has consistently chosen to publish information that we, and other retailers, have confirmed to be incorrect. This includes data for products that we do not even sell.”

A statement from Which? said that Lidl has “failed to say what the inaccuracies are”.

An Asda spokesperson said: “We’re working hard to keep prices in check for customers despite global inflationary pressures and we remain the lowest-priced major supermarket – a position recognised by Which? in their regular monthly basket comparison which has named Asda as the cheapest supermarket for a big shop every month for the last three years.

“We recently announced we would be freezing the prices of over 500 popular branded and own label products, more than half of which are fresh meat, dairy, fruit and vegetable products until the end of May.”

A Morrison’s spokesperson said: “This is an unprecedented period of inflation and we are working hard to keep prices down and competitive for our customers while maintaining high standards and availability in all our stores.

“We recently reduced the price of 1,000 popular products and remain committed to doing all we can to help when it comes to the cost of grocery shopping.”

An Ocado spokesperson said: “We continue to support our customers by investing in price across branded and own-brand products. We’ve also recently introduced the Ocado Price Promise so customers can be sure they’re getting great value.”

A Waitrose spokesperson said: “Although no retailer is immune to inflation, particularly with dairy products comprising the majority of this basket, we’ve been working hard to keep prices as affordable as possible for our customers – and have already committed a record £100 million to lower the prices on hundreds of everyday staples.”

Aldi declined to comment.

Sainsbury’s and Tesco were contacted for comment.