Ontario’s police watchdog is investigating an incident in which a cyclist was tackled to the ground by Toronto police officers during a traffic stop on Queens Quay.

The takedown — captured on video and shared widely online — occurred on Sunday, May 31, near Little Norway Crescent, where police were conducting a stop‑sign enforcement blitz.

The near-one-minute clip, posted to X by cycling advocate and personal injury lawyer, David Shellnutt, shows two officers forcefully bringing a cyclist to the ground as bystanders react in shock. In the video, which shows only a portion of the interaction, the cyclist can be heard asking, “What did I do wrong?” while an officer responds, “You didn’t stop.”

In a statement, Shellnutt said Thursday his client was not assessed or treated by officers at the scene, despite having an “obvious head injury” after being tackled off his bike.

“Our client has been diagnosed with a head injury/concussion and given a referral to a head injury clinic,” Shellnutt said. “His concussion symptoms remain ongoing.”

The cyclist was issued three provincial offence notices, though police did not specify the exact charges.

The Special Investigations Unit (SIU) confirmed Thursday that they had invoked their mandate.

The unit is an independent government agency that investigates the conduct of police officials that may have resulted in death, serious injury, sexual assault and/or the discharge of a firearm at a person.

Police sources tell CityNews that the encounter began after the cyclist rode through a stop sign and began shouting profanities at the officers.

According to police sources who have watched multiple angles of the body worn camera footage, in an attempt to flee police, the cyclist is seen hitting a curb and falling onto the grass. An officer who was following the cyclist then falls on top of him during the interaction.

Police say the cyclist then attempted to flee on foot. An officer is seen pulling the individual down by his knapsack. Sources say the cyclist allegedly began resisting arrest while the responding officer attempted to place him in handcuffs. Other officers provided assistance when they saw the two fall to the ground.

Police sources are disputing claims that paramedics were not present during the interaction. They say paramedics were driving by on their way to another call. They stopped at the scene and assessed the cyclist. The cyclist reported a scraped knee and declined further medical attention. The body worn camera footage confirms the cyclist did sustain a scraped knee. It does not show any obvious head injury to the cyclist.

CityNews has not independently seen or confirmed the body worn camera footage.

The incident comes as Toronto enters peak cycling season and amid ongoing debate about how the city enforces traffic laws on the waterfront trail. In years past, police faced criticism for similar blitzes targeting cyclists rolling through stop signs.