The Food and Drug Administration conducted a search of the Las Vegas offices of ChemNutra, supplier of the ingredient suspected in the contamination of millions of cans of recalled dog and cat food, the company said Friday.

ChemNutra said it had been informed the company could be held accountable because it imported the melamine-adulterated wheat gluten used in the tainted pet food even though the company had no knowledge its supplier in China had introduced melamine into the product.

"We have cooperated and complied fully with FDA investigators both prior to and since being served with today's search warrant, and will continue to do so," Steve Miller, chief executive officer of ChemNutra Inc., said in a statement. "We keep very good records, which has made it relatively easy for the investigators to retrieve what they needed."

Click here to view a list of recalled pet foods.

A spokeswoman for the FDA, Julie Zawisza, would neither confirm nor deny a search warrant was executed.

A ChemNutra spokesman said he would be available later Friday to answer questions about this latest development in the ongoing case.

Menu Foods Midwest, an affiliate of Menu Foods Ltd., the company that recalled 60 million cans of pet food, earlier this week filed a lawsuit that seeks to have ChemNutra pay the costs of the recall plus damages.

ChemNutra maintains Menu Foods waited several weeks before notifying it about the problem. ChemNutra also says Menu Foods had other suppliers of wheat gluten.

Menu Foods Ltd., based in Streetsville, Ontario, recalled its products after 16 pets, mostly cats, died from eating contaminated food. Other manufacturers also recalled animal food.

The lawsuit, which lists Menu Foods Midwest, Menu Foods Ltd., Menu Foods Holdings Inc. and Menu Foods Inc. as plaintiffs, accuses ChemNutra of breach of contract and breach of implied warranties about the safety of the wheat gluten and its fitness for use in pet food. It said each shipment of wheat gluten came with a certificate saying it met Menu Foods' requirements.

"ChemNutra knew that Menu Foods was relying on ChemNutra's skill and judgment to supply high-quality wheat gluten," the lawsuit said.

Menu Foods said it faces more than 50 lawsuits.

Click here to view a list of recalled pet foods.