Residents in Hepworth will have to head up the road to collect their mail for the time being.
On Thursday, a notice was issued by Canada Post that the office, located in Cindy's Variety along Bruce Street, was temporarily closed.
All PO Box mail and parcels needing to be picked up will be transferred to the Wiarton Post Office.
Canada Post spokesperson Phil Legault said the closure was "for reasons beyond our control."
There is no timeline for when it will reopen, as Legault said Canada Post "will work with elected officials to determine the future direction of postal services for customers in Hepworth."
Grey Bruce OPP would not confirm or deny whether the closure was due to an ongoing controlled substance investigation.
"Our policy is not to disclose the exact address whether it be a residence or business of a crime therefore I am unable to confirm the details," said Provincial Constable Krista Linthorne in an email.
The Wiarton Post Office is open Monday to Friday from 8 a.m. to 5 p.m. and Saturdays from 9 a.m. to noon.
