The Co-op grocery chain has recalled 165,000 hollow milk chocolate Santas after small button-cell batteries were found inside a number of items.
A spokesman for the company said it had informed the police and Food Standards Agency of the "alleged tampering incidents".
The two treats containing batteries were found at two separate locations, one in Suffolk and one in Essex. There was no indication of any blackmail demand or threat.
Customers have been advised not to eat the chocolate figurines but to instead call Co-op for a refund.
A Co-op spokesman said: "The health and safety of our customers is our top priority.
"We are concerned about two separate instances of alleged product tampering involving our hollow milk chocolate Santa foil figures, which have been found to contain a small battery inside."
The Co-op said no other products are affected.
Anyone who is concerned should call Freephone 0800 0686 727.