A male robbery suspect who evaded police in Barrie and fled to Toronto’s Union station on Monday remains on the loose but may have been shot during the chase, the province’s Special Investigations Unit says.

At about 4 a.m. on Monday, Barrie police officers found four persons of interest in a robbery investigation at a gas station in the St. Vincent and Grove streets area of that city and attempted to stop them.

All four — described by the SIU as two males and two females — fled in a vehicle.

Officers gave chase and during the pursuit one of the officers discharged his firearm.

The fleeing vehicle then struck a tree and police arrested three of the four occupants after a short chase.

The fourth suspect, a 21-year-old man, was not found and police believe he later boarded a GO train or bus headed for Toronto’s Union Station.

Toronto police searched the station but were unable to locate him.

Barrie police later said he may have his right arm in a sling.

The SIU says they have collected evidence that suggests his injury is the result of a gunshot by police.

He is described as a black male with a thin build, standing six-feet-tall, with dark hair in dreadlocks.

He has a goatee and was last seen wearing white or beige pants and a white long-sleeved shirt.

The SIU is called to investigate any incident involving an Ontario police officer and a member of the public that results in death, serious injury or an allegation of sexual assault.