Police were called to the scene after guests reported feeling dizzy and disoriented, and some were experiencing nausea and vomiting.

The incident took place at a retirement community in Whitestone, Ontario, Canada, where cannabis was legalised for recreational use last year.

Ontario Provincial Police Constable Miles Loach told CBC News that police were trying to determine where the brownies came from.

He said: “These luncheons are catered. It’s still part of the investigation whether that was what happened [that] somebody brought the wrong batch or somebody spiked them.”

A spokesperson for the police added that nobody had suffered any long-term effects.