TORONTO -- An Ontario cashier says she felt something wasn’t right when a senior tried to purchase about $3,000 worth of Google gift cards.

Cathy Lumia, who works at a Shoppers Drug Mart in Uxbridge, Ont., said she immediately noticed red flags with the purchase.

“It sounded very fishy an elderly person coming in to buy $3,000 worth of Google gifts cards,” Lumia said.

Cashiers are trained to ask questions if something doesn't seem right and Lumia said she felt the senior seemed scared and also didn’t want to answer questions about the large purchase.

“I asked her, did they tell you not to speak with anyone about this situation and she said yes that's correct. ‘I’m not to talk about it with anyone,’” Lumia recalled.

Lumia says she spoke with her manager and they both agreed the woman should not go ahead with the purchase. Lumia explained to the woman she had likely been targeted by criminals involved in the CRA tax scam.

Police say gift cards are often used by fraudsters as payment because they can't be easily traced.

Det. Doris Carriere with the Financial Crimes Unit at Durham Regional Police said unfortunately many people get duped by scammers this way.

“The scenario is typical of what we see. There are different ways to get money and the gift card is one we see quite often,” Carriere said.

To avoid becoming a victim of fraud be cautious if someone you don’t know contacts you by phone, email or texts and makes demands. Especially if they tell you not to discuss what they told you with anyone.

Don’t give out personal information and remember the Canada Revenue Agency does not accept gift cards as a form of payment. Also, be cautious if you are asked to send funds using Bitcoin or wire transfers.

Lumia says she was glad she stepped in to prevent the fraud from happening and says other cashiers who notice red flags in the checkout lane should also ask questions.

“I feel fantastic because these scammers didn't get the Google cards and I saved her (the senior) a whole lot of money," said Lumia.

It’s important to know scammers can "spoof" phone numbers so it may appear they are calling from the tax or police department.

It’s also a good time to warn seniors and others to be aware of this scam so it doesn’t happen to them.