A suspicious letter is under investigation by Huntsville OPP. The authorities were made aware of the letter Friday after it was sent to the media. The letter threatens the safety of the beaches in Muskoka and seeks to undermine tourism in the area, while police say the beaches will be closed intermittently as investigators assess the validity of the threat. The Townships of Bracebridge and Gravenhurst report that hazardous materials were located on area beaches in early April, while investigators cannot comment on the type of material found. Townships say enhanced inspections of the beaches will make sure the sites are safe for beach goers. The OPP confirm they’ll utilize all required resources to determine the validity of the claims that were made. Further information will be provided only as the investigation continues.