Australian shoppers who have been sceptical of Aldi’s claim to offer the best deal on their grocery basket finally have an answer: independent research confirms its customers can save 25 per cent on their bills.

The first “basket of goods” report from consumer group Choice reveals mystery shoppers across Australia saved $17 on average when they filled a standard basket of goods at Aldi instead of supermarket giants Woolworths or Coles.

Shoppers were sent to 81 stores across the country to buy a list of 14 basic items: apples, carrots, Weet-Bix, sliced white bread, flour, penne pasta, white sugar, teabags, tinned diced tomatoes, a block of tasty cheese, full-cream dairy milk, frozen peas, beef mince and butter.

The average Aldi basket price came in at $51.51, with and without specials. Woolworths shoppers spent $68.58, or $64.93 with specials, while customers at Coles had the most expensive receipts, at $69.33, or $68.52 with specials.

It meant Aldi shoppers spent $17 less on the 14 items, or a 25 per cent saving.

The mystery shoppers deployed across the nation’s grocery stores were funded by the government, as part of its action on supermarket pricing. Prime Minister Anthony Albanese earlier this year announced a review into the Food and Grocery Code of Conduct, warning supermarkets to pass on any savings they make from suppliers to consumers.

The final review is expected this week but an interim report said compulsory regulations should be imposed on supermarkets to govern how they deal with suppliers, backed by heavy fines and new rules to address claims of price gouging and market manipulation.

Choice’s research has revealed there are slight variations in prices between states, but Aldi is consistently cheaper, while Coles and Woolworths have similar offerings.