PORTLAND (AP) — Businesses in Portland are being warned to be on the lookout for counterfeit $100 bills.

The Portland Downtown District sent an email to members on Monday alerting them to the threat after one was used at a business on Sunday.

Executive Director Janis Beitzer said counterfeit bills show up every year or so, but they are usually $20s — fake $100s are a bit unusual.

She said the bill passed Sunday passed the security test using a special marker, but a hologram printed on the bill did not show.

The Portland Press Herald (http://bit.ly/18KYKEn ) reported that anyone who believes they may have received a counterfeit bill or suspect someone of trying to use one is encouraged to call police.