Two men have been taken into custody over the altercation, which occurred in the street on Scheyville Road, Oakville.

The officer, a senior detective aged 45, was described to Fairfax Media as "very experienced".

Sources have told Fairfax Media the officer attended the street after reports of a neighbourhood dispute.

Ambulance officers were called to the scene after reports that "a police officer on [the] scene [was] struck in [the] head with an axe".

A police media spokesman originally said that the officer was "critically injured", however he has since died.

Police Commissioner Andrew Scipione is on his way to Windsor police station.

More to come...