You'd expect food from a supermarket's budget range to be inferior to their own brand range.

But that doesn't appear to always be the case according to an investigation by the Mirror .

Journalists tested several budget range products sold by Tesco, Sainsbury's, Asda and Morrisons only to find the equivalent product in the supermarkets' more expensive own brand range contained the same ingredients and nutritional values.

Some products came from same factory and even had the same product codes. The products could only be identified from one another by their price and packaging.

For example, the weight, ingredients and nutritional contents of cans of corned beef from Sainsbury's and Tesco were the same in both their mid-market and cheaper budget ranges.

Here are some more details on other products which appear to be the same in both ranges.

1. Tesco

Tesco cornflakes

Tesco, Everyday value cornflakes, 500g - 45p

Cornflakes, 500g - £1

DIFFERENCE: 55p

2. Morrisons

Morrisons milk

Savers UHT skimmed milk, 1L - 57p

Longlife skimmed milk, 1L - 88p

DIFFERENCE: 31p

3. Tesco

Tesco tinned potatoes

Everyday value new potatoes in water, 567g -35p

New potatoes in water, 567g - 65p

DIFFERENCE: 31p

4. Tesco

Tesco corned beef

Everyday value corned beef, 340g - £1.50

Corned Beef, 340g - £1.75

DIFFERENCE: 25p

5. Sainsbury’s

Sainsbury's corned beef

Basics corned beef, 340g - £1.50

Corned beef, 340g - £1.75

DIFFERENCE: 25p

6. Sainsbury’s

Sainsbury's flour

Basics self-raising flour, 1.5kg -60p

Self-raising flour, 1.5kg - 85p

DIFFERENCE: 25p

7. Asda

Asda corned beef

Smartprice Corned Beef, 340g -£1.47

Corned Beef, 340g -£1.67

DIFFERENCE: 20p

8. Asda

Asda tinned peas

Smartprice garden peas in water, 300g, - 21p

Garden peas in water, 300g - 40p

DIFFERENCE: 19p

9. Morrisons

Morrisons honey

Savers clear honey, 340g - £1

Clear honey 340g - £1.13

DIFFERENCE: 13p

10. Morrisons

Savers salted butter, 250g - £1.50

Morrisons Savers butter

Salted Butter (250g) - £1.60

Morrisons own brand butter

DIFFERENCE: 10p

Tesco said: “We want all our own-brand products [to] offer real value and are reviewing our approach to these.”

Sainsbury’s said: “There are many factors which inform product specification. This will dictate the range it is in.”

Asda said the products had the “same overall ingredients” but “gradings differ”.

Morrisons said: “Savers butter is sourced from inside and outside the UK. Stan­dard butter will always be British.” And its Long Life milk has “clever” packaging.