Warning as fake $50 notes circulated at Royal Adelaide Show

Fake $50 notes have been found in circulation at this year's Royal Adelaide Show, putting stallholders on alert.

So far three counterfeit notes have been found at the show, which is causing frustration among those trying to sell items and experiences at the Wayville Showgrounds.

South Australia Police confirmed one fake $50 note was used to buy showbags, another was used to buy food and today another stallholder found a new fake note.

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Stallholder Adam Oaklands said a lot of people put lots of time and effort to make their products.

"It's a bit of a shame that people try and take advantage of it," Oaklands said.

"We are being a little bit more vigilant in regards to our cash sales and spend a little bit more time with what is coming through our tills," he said.

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Police Commissioner Grant Stevens said police were going down every avenue to identify the people involved and take appropriate action.

"We do have a lot of people coming through the venue so there is that opportunity for people to take advantage of that heavy movement," Stevens said.

Stallholders are being urged to check the colour of each note they recieve.

The show is on until Sunday.