LEWISTON — A man in his 20s came into Save-A-Lot Thursday. He picked up a few items and handed the clerk a $50.

It was counterfeit.

“I gave him back two $20s,” cashier Kabrina Leclair said Friday. “If I was not in a rush I would have caught it.” The bill didn’t feel like money, it was thicker, she said of her first encounter with counterfeit money.

On Friday, store manager Carol Landry said the bank confirmed the bill was fake; her store was essentially robbed. She feels lucky it was only one counterfeit bill. She’s advising her staff to be on the lookout. “If you think it’s funny, if you don’t feel comfortable,” decline to accept it.

The Lewiston Police Department is also warning businesses to beware of counterfeit bills. That warning came Friday after police received numerous reports of fake $50s and $20s passed off at stores Thursday. More reports are coming in from southern Maine, “from Lewiston all the way down to Damariscotta,” said Lewiston Police Department Lt. Mark Cornelio.

Counterfeit money given to stores Thursday looked real, but “it was much heavier. The paper was thicker than the normal bills,” Cornelio said.

Store clerks used to handling money may feel the difference right away, he said. If anyone is unsure, hold the bill up to the light to look for embedded security lines or water marks. “Know your currency,” he said.

Auburn Police Department Lt. Tim Cougle, commander of criminal investigations, said use of counterfeit bills is up slightly. In recent months Auburn businesses have been given fake $10, $20, $50 and $100 bills. The fake money is mostly passed off at convenience stores and grocery stores.

The increase is due in part to advanced scanners, he said. “It’s easier for an average person to attempt. The quality varies.” Some look authentic, others don’t, leaving Cougle shaking his head as to how they were accepted. While fake bills may look good, they don’t feel right, Cougle said, agreeing with Cornelio.

According to the U.S. Treasury Department, bills printed in the last several years have numerous security marks, including, color-shifting ink on bills higher than $5. When tilting the bill back and forth, the numbers in the lower right corner shifts from green to black and back. Authentic bills also have embedded watermarks to the right of the portrait that match the portrait, as well as embedded security threads running from top to bottom.

For more information: www.ustreas.gov/offices/domestic-finance/acd/if-you-suspect.shtml