The report by the agency that investigates complaints against police concludes Adam Nobody, who was arrested at the provincial legislature in June 2010, made substantiated allegations.
The report calls on Chief Bill Blair to lay Police Act charges against five officers.
"They beat me up tremendously bad," Nobody, 28, said in an interview Friday.
"I had another human being stepping on my face, grinding my face into the ground. It's appalling."
The report by the Office of the Independent Police Review Director names constables Babak Andalib-Goortani, Michael Adams, Geoffrey Fardell, David Donaldson and Oliver Simpson.
It concludes their behaviour hurt the reputation of the police force and was of a "serious nature."
To date, only Andalib-Goortani has been charged criminally — assault with a weapon — in relation to Nobody, one of more than a thousand people arrested and detained that June weekend.
However, the provincial police watchdog known as the Special Investigations Unit closed the case last July, saying it could not identify any of the other officers involved in Nobody's arrest during which his cheekbone was broken.
"I do feel a lot more vindicated that the other officers were named and even their identities were produced," Nobody said.
"The chief of police should be pressing charges."
Seven weeks before the Nobody arrest, Adams was also involved in the death of a Junior Manon, 18, who died from "positional asphyxia" when police restrained him during his arrest.
The SIU found no grounds to press criminal charges, but the death is the subject of an inquest that began this week.
"The force used to arrest him was not excessive," SIU director Ian Scott said at the time.
Nobody's lawyer, Paul Copeland, called it troubling that Adams was part of the G20 police presence given that he was still under investigation at the time in the Manon case.
"I have some concerns that he's out on the street interacting with the public while the SIU investigation into him is going on," Copeland said.
The new 172-page report cites Adams as admitting to having hit or punched Nobody in the face three or four times during the arrest.
Manon's family wants to cross-examine the officer at the inquest on the information in the report.
Julian Falconer, who represents the Manon family, said they have good reasons to want to take a closer look at Adams' behaviour.
"This has all the appearances of a pattern of excessive force," said Falconer, who does not speak for Nobody.
"They want that pattern fully explored."
Mike McCormack, the head of the Toronto Police Association who speaks for the accused officers, expressed concern at how long it has taken to recommend the Police Act charges.
"That puts a lot of undue stress on our officers," McCormack said.
"They're well out of the six-month limitation to lay charges."
McCormack disputed Falconer's suggestion of a "pattern of behaviour" by Adams, saying there's "no evidence" he used excessive force in Manon's case and the Nobody allegation has yet to be tested.
Toronto police did not respond to a request for comment.
The new complaints report concludes the officers had reasonable grounds to arrest Nobody, but then used unnecessary force.
Nobody, who needed reconstructive nose surgery, called police suggestions that he was resisting arrest or being violent toward the officers "ridiculous."
He said he was waiting for conclusion of Andalib-Goortani's criminal case before pursuing a civil suit.
Copeland praised the new report for a "very effective job" of identifying the officers involved.
He said Blair should find someone independent to hear the misconduct charges, and called on the SIU to take a look at the report.
An SIU spokeswoman said the agency had just received the report and was "reviewing it."
Nobody said he was grateful for the witnesses and those who videotaped his arrest.
What he really wants, he said, is justice and an admission of police wrongdoing.
"I'm hoping that someone in the higher ranks admitting that they're wrong, and that the whole thing was completely unnecessary."