Brantford Police say investigators have determined the source of a mysterious pool of human blood discovered along the Grand River by hikers.

The pool of blood, which police estimate was about half a litre, was located under a old train bridge south of Lorne Bridge along a path that police say isn't frequently used by hikers. 

Detectives say they received a tip from the community, which led their investigation to the Niagara Region. Officers were able to locate a man who was "in crisis," police said. 

Police say the man has been taken to hospital to receive medical attention. 

Investigators say the incident is not considered a criminal act.