An eagle-eyed ALDI shopper has found a little known fact on the back of several supermarket goods.

She shared the findings on the popular Facebook group ALDI Mums and pointed out an easy-to-miss code on the back of ALDI's seafood products that provides information about which country and region the fish originated from. 

Australian products are required to have location details on the packs, but the extra known detail allows customers to source even more information.

All you have to do is flip your ALDI seafood item over and locate a number and use the digits to look up the information.

“I know seafood gets a bad call out,” the shopper posted to the group.

“I just wanted to share something with you all that I learnt and hopefully it will solve all the ‘do you know where your fish comes from’ dramas.”

She went on to explain that each box has a “code” for the fish area/catchment area it is caught.

“You can then look it up to know which areas your fish has come from and what practices they use.”

The shopper shared an image of her seafood buy, sharing the code "FAO 81", which reveals the catchment covers a significant part of the Southwest Pacific.

“Hope this helps everyone in the future,” she wrote.

Many of the Facebook members thanked the woman for sharing her handy tip.

“That’s great info! Thanks for sharing,” one person wrote.

“This is so helpful, thank you,” said another.

“Very useful information thanks for sharing,” a third commented, while a woman added, “Very interesting. I looked it up on Google. Great how it shows the world areas.”

The original poster explained that she understands that the German supermarket chain is making "great progress to be sustainable, responsible and accountable".

“Personally, I don’t buy non-Australian and was pleasantly surprised to see this info.”