UPDATE: All charges against Douglas Sherwood were withdrawn on the first day of his preliminary inquiry in January 2018.

A Calgary police officer is facing charges of assault with a weapon, assault causing bodily harm and uttering threats after it's alleged he drove into a man before getting into a fight while off duty.

Police say Douglas Sherwood, 41, saw a man acting suspiciously in his northwest Calgary neighbourhood and confronted him back in January 2015.

Officer confronted prowler

It's alleged he got into his truck and began to follow the man down the street.

The man kicked the officer's truck after he was questioned about what he was doing in the neighbourhood and why he was in a neighbour's backyard.

The officer did not identify himself to the man as a Calgary police member.

Police say the officer used his truck to strike the man from behind before getting out of his vehicle and starting a physical altercation.

Neighbour called 911

A resident in the neighbourhood saw what was happening and called 911.

It is also alleged that the officer verbally threatened the man. Both the officer and the man were injured in the fight.

Sherwood is charged with one count each of assault with a weapon, assault causing bodily harm and uttering threats.

He will next appear in court on May 15.