What procedure should be followed if a food product is suspected of being adulterated i.e., contaminated?

it depend on the stage is this product on th market or still in the industry. whatever

for the first case i think we should communicate of our costumers  and come-back our product we call it " systeme de rappel des produits" in frensh but its very difficult position because its very hard for the business and company reputation.

for the second case  we start by isolate the product and sampling a