SIU/handout This is the location, on Adelaide Street in downtown Toronto, where the police vehicle was parked.

The Ontario Special Investigations Unit's (SIU) decision not to charge a Toronto police officer for dooring and injuring a cyclist is unacceptable and shameful, road safety advocates say. The officer was "clearly to blame" for the incident that left the cyclist with a fractured wrist in June, SIU director Tony Loparco wrote in a report. The police officer parked his cruiser on a downtown street, on a bike lane, after pulling over a vehicle. He did not put on his emergency lights. Three cyclists passed the stopped cruiser on the driver's side, before the officer fully opened his door and struck a fourth cyclist, causing the cyclist to fall to the ground. The officer did not "take the necessary precautions when he opened his door into bicycle traffic and thereby caused the injuries," Loparco said.

Andrew Lahodynskyj/Getty Images Special investigations Unit truck and Toronto police officer on July 24, 2016.

But that's not enough to charge the officer for criminal negligence causing bodily harm, said Loparco. The officer also hasn't been charged under the Highway Traffic Act despite the fact he "may well be liable" for such an offence. Toronto police did not respond to HuffPost Canada's request for comment. "His indiscretion amounted in essence to a momentary lack of attention and fell short of constituting a marked departure from a reasonable level of care in the circumstances," said Loparco. "Consequently, I'm satisfied that there are no basis for proceeding with criminal charges." Road safety activist and Toronto injury lawyer Patrick Brown said the SIU, which is responsible for investigating police incidents of death, sexual assault or serious injury, is sending out "a very poor message" about cyclist safety. "They don't take it seriously," Brown told HuffPost Canada. "The message they sent out to the public is that dooring is not a big deal, not even warranting of a ticket." WATCH: Safe cycling tips for Toronto streets