Former Ontario Superior Court judge John Hamilton is presiding over the police hearing for Supt. Dave (Mark) Fenton after the previous retired judge appointed to the case withdrew for medical reasons.
But lawyers for two complainants involved in the case say they've learned "there is a real concern that there may be a reasonable apprehension" that Hamilton could be biased in favour of police officers.
They say the concerns came to their attention through a recent editorial in the Toronto Star, which said the perception of bias had become an issue.
In a letter sent to Toronto Police Chief Bill Blair, lawyer Paul Cavalluzzo says he understands that Hamilton represented police officers before the courts during his time as a lawyer in the past. He says proceedings such as Fenton's hearing "must not only be impartial, they must also be seen to be impartial."
The letter asks Blair, who appointed Hamilton, to provide any information related to the retired judge's past dealings and relationships with Toronto police or any other police officers in Ontario.
A spokesman for Blair said the police chief was out of the office and had not yet had an opportunity to see the letter, but there would be a reply "in due course."
Meanwhile, a prosecution lawyer appointed to the hearing said the matter was within Blair's jurisdiction and that since no motion for Hamilton to recuse himself had been brought up at the proceedings, the case would be progressing as normal.
A lawyer representing other complainants in the case said she was still waiting for instructions from her clients.
Fenton's defence lawyer did not immediately respond to a request for comment.
Fenton has pleaded not guilty to a total of five charges under the Police Services Act of unlawful arrest and discreditable conduct stemming from two "kettling'' incidents that occurred over the G20 summit weekend.
The first took place on Saturday, June 26, 2010, hours after a small group of vandals smashed windows and set police cruisers alight.
Fenton ordered officers to box in protesters in front of a downtown hotel. More than 260 people were arrested and taken to a makeshift prisoner processing centre, which came under severe criticism for its deplorable conditions.
The second incident occurred the next day when, six minutes after coming on shift, Fenton ordered police to keep scores of people standing for hours at a downtown intersection despite a severe thunderstorm that left them drenched.