Counterfeit dollar bills may not always be easily identifiable, but an eagle-eyed Butterfield and Vallis employee spotted one this week.

Giovanni Lema observed a friend's US $5 bill was yellowish in colour.

"If you put the bill up to the light, you can see a line. There was no line on this bill," Mr. Lema said.

The line on the bill that Mr. Lema tested should have appeared on the left side of the face and stated USA 5 when put up to the light.

Mr. Lema also marked the bill with a marker that is specifically made to detect counterfeit bills. When the marker was used on the bill it turned black identifying that it was a counterfeit bill, Mr. Lema said.

"I had a friend laminate it and now it's sitting on my desk," Mr. Lema said.