Police say a man has been attempting to use counterfeit cash at downtown Port Jefferson stores at least four times over the past week. 

The incident was reported to police on June 3 after NSI Design says the man used a counterfeit $100 bill to make a purchase.

Police say the man also tried to use the fake cash at Port Jefferson Liquors, A Pattern Finders and East End Shirt Company.

Business owners say the suspect was able to hit so many stores in such a short amount of time because many of the shops are so close to each other.

For example, NSI Design furniture store is just about 100 feet away from the liquor store. However, the owner of the liquor store said he knew something was wrong.

Stephen Plunkett says the scammer was looking for a small bottle of vodka and only had $100. Plunkett said the man was acting weird and that caused him to stare at the bill. He did not accept the bill. Plunkett says, as a small business owner, losing $100 would have hurt and insurance wouldn't have covered the loss.

Business owner Sharon Zalinger says her maternal instinct allowed her to be scammed by the man. She said he needed a gift for his mom who put him through medical school and he said he didn’t have a lot of money.

Zalinger says she will now check every large bill before accepting it.

Police have released an image of the man they believe to be the scammer. 

Authorities are urging anyone with information about the incident to call Crime Stoppers at 1-800-220-TIPS.