The Canadian Food Inspection Agency (CFIA) is cautioning the public after reports of tampering in an infant formula product at an Edmonton Walmart.

According to the agency, the reports come from the Walmart store at 775 Tamarack Way NW. The agency did not say which brand or brands may have been affected.

Edmonton police confirmed Thursday afternoon they are investigating the alleged tampering at the Tamarack Way location, as well as at a Walmart located at 3931 Calgary Trail NW. Police said they are investigating the tampering incidents "as frauds, as opposed to having any malicious intent."

"Infant formula products have been found where the tamper-proof seals had been broken and the product inside the containers had been substituted," read a CFIA advisory issued Wednesday.

The issue is not usually from the manufacturing process, but from a consumer returning altered products for a refund, the agency said.

The advisory did not state what product had been substituted for the formula.

Emily Myrehaug bought Similac infant formula last month at an Edmonton Walmart she believes was tampered with. The container on the right shows normal product and the one on the left is the container she thinks was replaced with flour. (Emily Myrehaug)

Emily Myrehaug of Spruce Grove said she purchased a container of Similac formula last month from the Tamarack Way Walmart that she believes was actually flour.

"I opened it and I noticed that it was actually a different colour," said Myrehaug, mother of five-month-old son Breckan. "It was more brown-white. Usually it's very white, and obviously I could tell the difference and I thought it was kind of weird."

Myrehaug said that at first she thought the formula had gone bad, but decided to try it for herself.

"When I tasted the flour obviously I was pretty freaked out."

Myrehaug said the CFIA collected a sample of her formula for testing on Monday.

She said she noticed the broken seal on the container, but thought originally she might have opened the container herself earlier. She said she wanted to raise awareness to other parents to inspect their products.

"Always check, always look, always make sure. I could see easily see a mom that's exhausted at three in the morning, making it in the middle of night easily not pay attention and accidentally give her kid something."

The CFIA has not confirmed the advisory is related to the product purchased by Myrehaug, though she said her formula was tested by the agency on Monday.

In a statement emailed to CBC News, Walmart Canada said food safety is a top priority the company.

"We take these matters very seriously," reads the statement. "We are aware of the CFIA Consumer Advisory and are investigating further with our store at 775 Tamarack Way NW in Edmonton. The product in question has been removed from the store floor while we investigate."

In a later email, Walmart Canada said other area stores were directed to review the formula on the sales floor and the Walmart location at 3931 Calgary Trail NW also identified potentially tampered products. The company is working with local police and the CFIA on the issue.

Customers urged to examine products

Abbott, the maker of Similac, said product quality and safety are the company's highest priorities and it is investigating. In a statement, it added that consumers should report any product that looks suspicious.

"As precautions, our products are designed with tamper-resistant and tamper-evident seals, and we encourage consumers to always buy our products from authorized channels," said the statement.

"If anything looks suspicious with the packaging, label or contents, customers should not use the product in question and should contact our consumer care line at 1-800-670-7878."

The CFIA said no illnesses have been associated with the reports, but consumers are advised to examine their formula products and ensure the security seal is intact. Do not use products that appear to have been altered.