MISSISSAUGA, Ont. -- An investigation by one of Ontario's police watchdogs has turned up enough evidence to suggest a Toronto police officer committed a crime by kicking a man in the face during a raid but not enough detail to identify who delivered the blow, the agency's director said Wednesday.

Tony Loparco, head of the Special Investigations Unit, said the officer who broke the nose of the 24-year-old university student during a house raid last October would likely be facing a charge of assault causing bodily harm based on accounts uncovered during a probe of the case.

After interviewing civilian witnesses and either speaking with or reviewing the notes of dozens of officers, however, Loparco said the SIU was unable to determine the identity of the specific officer involved.

“I believe that the force was unnecessary, excessive and amounted to an assault,” Loparco wrote in a report dated Sept. 18 and released on Wednesday.

“Nonetheless, although I have ground to believe that some officer committed a criminal offence, I am unable to identify the specific officer who committed the impugned act ... There is accordingly insufficient identification evidence to form reasonable grounds against any particular officer and thus no charges will issue.”

Toronto police did not offer comment on the SIU's findings and did not immediately respond to specific questions. The force released a brief statement saying its professional standards unit is conducting an ongoing, parallel investigation into the case.

“It is normal procedure we conduct a parallel investigation in SIU matters,” the statement read.

Loparco said the incident began on Oct. 23, 2017 after 11:00 p.m. when officers with both Toronto police's emergency task force and drug squad came to arrest the unidentified man at his home in north Toronto.

According to Loparco's report, the man had allegedly sold drugs to an undercover officer and also offered to sell a firearm.

Loparco's report states an unspecified number of ETF officers began “flooding the house with uniformed police officers - most wearing balaclavas.” Other officers were deployed outside the home.

Loparco's report said police came upon the man in a hallway and ordered him to lie on his stomach on the floor of the hallway. The man complied.

When an officer arrested him a short time later, Loparco said the man had a bloody nose, swelling under the left eye and cuts to his face. He was taken to a local hospital where he was diagnosed with multiple fractures to his nose.

The man told investigators he suspected he was kicked because he had moved his head while lying on the ground, the report said.

“It is alleged that the complainant's injuries were caused when an officer kicked the complainant on the left side of his face, in the cheek area, while he was on the ground,” Loparco wrote. “In my opinion, the complainant is both a credible and reliable witness.”

Loparco said the SIU, which investigates incidents involving police in which someone is killed, injured or accused of sexual assault, began probing the case on Oct. 27.

He said investigators interviewed three civilian witnesses, including members of the man's family. They said they were not able to identify the officer who delivered the kick because police in similar-looking uniforms were “pointing guns at them and yelling at them.”

Loparco said the SIU interviewed all members of the police's drug squad and many members of the emergency taskforce, none of whom were able to identify the officer.

The report did not provide updates on the man's condition or the allegations made against him.