It was a stressful few hours for the staff and students of Central Huron Secondary School in Clinton on Monday.
Huron OPP say they were called to the high school to the report of someone with a weapon entering the building.
When they arrived, officers located the person (a male) standing outside the school. The male was searched by police, but no weapon was found.
Police say their investigation proved the male never posed a threat to the staff and students at the school. No chargers have been laid in the investigation.
Officials with the Avon Maitland School Board told CKNX News after the lockdown was lifted that the OPP did not plan to press any charges in the case.
The lockdown was ended just after 2 p.m.
No one was injured.