Paramedics responded to a medical call at a restaurant on West Street at the intersection of Dundas Street on Monday shortly before noon.
Police officers also responded to assist the paramedics, who assessed, treated and transported a male patient to the Brantford General Hospital.
The patient passed away.
Const. Natalie Laing said that, as result, the call has been labelled “a sudden death.”
She added that there is no criminal investigation underway. Officers are only assisting with the investigation.