A well-known Toronto defence lawyer is joining the fight against alleged police brutality at last year's G20 summit.

Clayton Ruby has launched a lawsuit on behalf of a man who is accusing police officers of breaking his arm during the two-day summit in Toronto last June.

Ruby made an official announcement Wednesday afternoon about the case from the Yorkville offices of Ruby and Shiller.

A news release from the firm says the suit names the Toronto Police Service as well as seven unidentified officers in relation to the arrest and detention of Dorian Barton. The officers, though unidentified, were picked out from photographs of the scene that were provided by the public.

Barton, 29, maintains that he was merely a spectator at Queen's Park, which was designated as the official protest zone during the G20. He says he was struck by a police shield and arrested after taking a picture with his iPhone.

His claims have not been proven in court and police have not yet filed a statement of defence.

Though his case was investigated by the province's police watchdog agency, the Special Investigation Unit, officials deemed there was not enough evidence to lay any charges.

"It is very concerning that the SIU was unable to identify any of the officers who were involved in the (alleged) beating of Mr. Barton" Ruby said in the release.

Ruby said he is also concerned about the lack of paperwork available documenting his client's arrest. Barton was eventually released from custody with charges against him withdrawn.

"If there were charges, there had to be paperwork and a sworn criminal Information. Where is the paperwork? It will identify the officers," Said Ruby.

Ruby said his client wants the SIU to reopen their investigation.

If the SIU reopens their investigation, it will be the second time they have done so as a result of the public coming forward with new evidence from the scenes of the G20 summit.

On Dec. 21, Toronto police constable Babak Andalib-Goortani was charged with assault with a weapon in connection with the beating of G20 protestor Adam Nobody, as a result of that second SIU probe.

His case is still before the courts.

Andalib-Goortani is the only police officer to be charged in connection with events that took place at the G20.