Barrie Police received a report of Halloween candy tampering on Thursday.
An 11-year-old boy received an individually wrapped cherry flavored Tootsie Roll, which had a pill inside it.
He had been trick-or treating in the area of Cundles Road West, near Emma King Elementary School
The candy has been sent for examination and further details will be released as they become available.
Investigators are urging parents who had children trick-or-treating in the Cundles Road, West area to be extra vigilant when checking candy.