A criminal inquiry is under way following the discovery of a battery inside a Co-op chocolate Easter bunny.
Police and the National Crime Agency are investigating the alleged tampering following the incident in Nottingham, the supermarket said.
A nationwide recall of the hollow milk chocolate bunnies has been issued as police investigate.
Tammy-Louise Dundon, from Bulwell in Nottingham, bought the Easter bunny for her daughter Sophia Wood.
The three-year-old saw the single-cell battery, similar to those found in hearing aids, as she bit the ears off the rabbit.
Ms Dundon, 26, told the Nottingham Post: “If my daughter had swallowed it, it doesn’t bear thinking about.
“This isn’t just a choking hazard. It’s corrosive – she could have lost her life.
A Co-op spokesman said: “We are concerned about one incident of alleged product tampering involving our hollow milk chocolate Easter bunny foil figure, which has been found to contain a small battery inside.
“This follows an incident at Christmas when two similar products were targeted and contaminated.”
Just over 3,000 of the foil figure bunnies have been sold, at a cost of £1 each, and customers have been told they can return them to stores for a refund.