Police in Nanaimo are investigating several cases of possible food tampering after sewing pins were found in meat products purchased at grocery stores in the Vancouver Island city.

Three incidents have been reported to RCMP since the end of last year. All involved pins, similar to those used for sewing, that were found in Grimm's brand meat products.

In December, Nanaimo RCMP say a pin was found inside pepperoni sticks bought at Costco.

In February, a similar pin was discovered in pepperoni sticks purchased at the Real Canadian Superstore.

Most recently, a pin was found in a Ukranian sausage sold at the Fairway Market in March, police said.

"We believe through our investigation that it is happening while the products are on the shelves and not at the distribution centres," said Const. Gary O'Brien with the Nanaimo RCMP.

Police are warning anyone who has purchased meat products at Nanaimo grocery stores to inspect them thoroughly before consuming them.

Investigators are hoping Nanaimo residents will provide tips to help solve the cases, O'Brien said.

"Safe to say, it is not occurring anywhere else on Vancouver Island. There has been no food tampering reported within Canada within the last 12 months. It has only occurred in Nanaimo."

Grimm's and the grocery stores involved are cooperating fully with the investigation, O'Brien said.

No injuries have been reported as a result of the pins.