The Special Investigations Unit has invoked their mandate after a man was shot during an exchange of gunfire with a police officer in Etobicoke late Wednesday night.

According to the SIU, Toronto Police Service officers went to an apartment building on Willowridge Road near Martin Grove Road and Eglinton Avenue shortly after 11 p.m. to arrest a 23-year-old man.

The SIU says that there was an exchange of gunfire between the man and a police officer at some point, which resulted in the man being struck multiple times.

CP24 has since learned that the shooting took place in a parking lot outside the building as plain-clothes officers prepared to execute a search warrant related to an illegal weapons investigation. The officers decided to try to apprehend the suspect outside the building after they observed him arriving in a car, sources have told CP24.

On Thursday morning three vehicles were visible behind the police tape set up outside the building. Two of the vehicles appeared to be boxing in the third vehicle, which had bullet holes in its back window.

Police have previously said that between 10 and 20 shots were heard on Wednesday night and and that a firearm was located at the scene.

The male was taken to hospital in serious but non-life threatening condition, where he is in the custody of police.

The SIU has designated one subject officer and nine witness officers as part of their investigation.

They are also asking anyone who may have information about the incident to contact investigators at 1 (800) 787-8529.

Forensic investigators with the SIU were seen collecting evidence at the scene overnight but they left at around 7 a.m. Toronto police, meanwhile, continue to hold the scene.

The SIU is an arm's-length agency that is called in any time a police officer is involved in a death, serious injury or allegations of sexual assault.