The provincial police watchdog is investigating how a man ended up with "serious" injuries after a rooftop police chase early Wednesday.

According to the Special Investigations Unit (SIU), Hamilton police officers were called to a home on Barton Street East just after midnight for a domestic situation.

The officers recognized one of the individuals involved, a 41-year-old man, as being wanted on "outstanding warrants."

The man then tried to get away from police, the SIU says, by jumping from rooftop to rooftop.

The officers chased and fired at him with a Taser, an SIU news release reads.

The man was then taken to Hamilton General Hospital for treatment of a rib injury.

The SIU did not specify how exactly the man sustained that injury, or if he fell from a rooftop after he was shocked.

Hamilton police did not announce the incident at the time it occurred, or in any subsequent news release.

Shawn Munro told CBC News he saw the SIU investigators canvassing the scene on Wednesday around 9 a.m.

A photographer was on the roof of one of the buildings at the time, and numbered yellow cards used to mark evidence were placed on the ground below.

"There were six or seven of those scattered around on the ground," he said. Investigators were also searching a nearby alley.

The SIU says it has assigned three investigators and one forensic investigator to the case.

The unit is called in to investigate reports involving police where there has been death, serious injury or allegations of sexual assault.

Anyone with information about the investigation is being asked to contact the lead SIU investigator at 1-800-787-8529 ext. 2314.