FAKE $50 notes are still causing problems for shop owners in Hervey Bay, even though the alleged perpetrator of the scam has been arrested.

Rob Marturano from Hoffie's Corner Store and Takeaway was paid with one of the counterfeit notes on Monday afternoon, but did not realise the note was fake until later when he looked at it more closely.

The note looks much the same as a legitimate note, except for a few tells, such as the stars in the clear window being slightly out of position.

Mr Marturano said it was important other shop owners and residents were aware that the fake notes were still in circulation.

"People need to keep an eye out," he said.

Hervey Bay Criminal Investigation Branch confirmed on Tuesday that a person allegedly behind the counterfeit money operation had already been arrested.

The arrest followed six reports of counterfeit money in Hervey Bay throughout December.

Earlier, Criminal Investigation Branch head Detective Senior Sergeant Nikki Colfs said the 34-year-old Kawungan man was charged with eight charges related to counterfeit money, along with some unrelated drugs charges.

While some of the fake $50 notes are still in circulation, residents who are concerned they might have been passed a fake note can go to banknotes.rba.gov.au for a list of factors to determine authenticity.