Canadians are being warned to keep an eye out for counterfeit $100 polymer bills after seven imitation notes were discovered late last month in British Columbia.

The mock bills, which lack several of the security elements featured on the genuine notes, were first reported on April 28 when a grocery store in B.C. mistakenly accepted two fake $100 notes, police in New Westminster said.

"This is the first instance where we’ve seen them being counterfeit," Sgt. Diana McDaniel told CTV British Columbia on Wednesday. Several days after the first fake bills were discovered, police said five more imitation bills were reported when an individual attempted, unsuccessfully, to deposit them at a bank.

McDaniel said it’s possible that some people may have mock notes in their wallets without knowing. "We want to alert the public that if someone is coming to purchase something, they may have counterfeit bills mixed in with legitimate bills."

Launched in 2011 as one of Bank of Canada’s new line of upgraded bank notes, the polymer $100 bills feature a number of improved security elements intended to make it difficult to counterfeit bills.

But McDaniel said the phoney bills found in B.C. lack three key security features:

The Canadian flag on top of the building in the holographic inlaid image

The reflective '100s' in the holographic inlaid image near the missing flag

Raised ink

According to Bank of Canada Governor Mark Carney, since the unveiling of the notes, counterfeiting rates have dropped 92 per cent from their peak in 2004.

That statistic, however, isn’t reassuring local B.C. business owners who say they are shocked by the discovery.

"With all the security features that we were told about, it’s quite amazing that it can be done," owner of New West Cycle Shawn Innes told CTV News.

Police said an investigation is underway, and that no one has been arrested yet.

Individuals concerned about the authenticity of their $100 polymer bills can either have them checked at a bank, or refer to the Bank of Canada website for images of the legitimate bills.

With files from CTV British Columbia