LAWRENCE (CBS) – A .45 caliber bullet was found in a seemingly sealed jar of Teddie Peanut Butter at the School for Exceptional Studies in Lawrence on Monday, police said.

A student had brought the jar in from home.

School officials say a teacher’s aide found the bullet while scooping peanut butter from the jar.

The student’s mother told police she purchased the peanut butter at a local Market Basket. The store has pulled similar jars off the shelves since the incident.

The president of Teddie Peanut Butter told police that the company uses metal detectors that could detect even a small pin in the product.

WBZ NewsRadio 1030′s Bernice Corpuz Reports

Police are working with the FDA to try and figure out how the bullet ended up in the jar.

“Our purpose is to try to find out how, when, and where this item may have been introduced into the peanut butter,” said Captain Michael Driscoll.