A woman who says she was unlawfully detained by police during the G20 summit protests is the lead plaintiff in a $45-million class action lawsuit against police.

The suit was filed on behalf of Sherry Good in the Ontario Superior Court on Thursday, her lawyers announced at a news conference at Queen's Park on Friday.

Good, an office administrator who lives in downtown Toronto, says she was in a group of hundreds of people who were surrounded by police near Queen Street and Spadina Avenue and held for hours in a rain storm on June 27 in a crowd control manoeuvre known as kettling.

"I am just an ordinary person, I am not an organizer, I am not an activist, but I got caught up in the police kettling operation at Queen Street and Spadina Avenue," Good said.

"I just feel that what happened to me and hundreds of others was very wrong. It shocked me that I was surrounded and held by police because I was just walking on the street where I live."

Police have said they thought they detected a group in the crowd that was about to break out and use Black Bloc tactics to commit vandalism, as happened on June 26. As a result, they corralled the entire group.

More than 1,100 people were detained on the weekend, which has been described as the largest mass arrests in Canadian history. In the immediate aftermath, police said they laid criminal charges against 263 people. The majority were released without charge within 24 hours.

Lawyers Murray Klippenstein and Eric Gillespie will represent Good.

Klippenstein called for a judicial inquiry into police actions during the summit.

"The money asked for in the lawsuit is not the real point," he said.

"The real point is to repair the damage that has been done to our Canadian society and our basic assumptions about our freedom by those hundreds of what seemed to be arbitrary arrests.

"This lawsuit will seek to bring about the facts, to establish accountability and to reaffirm our freedoms."

The notice of action will have to be certified by the court in order to move forward -- a process which can take several months.

If the suit proceeds and is successful claimants may be eligible for financial reward.

Toronto Police say they have yet to be served with the lawsuit and will not comment until that happens.

Violence broke out during the G20 summit protests in Toronto at the end of June. A small group of black-clad vandals emerged from a peaceful protest on June 26 and went on a spree of destruction, smashing store and bank windows and burning police cars.

The Ontario government isn't named in the lawsuit, but came under heavy fire for widespread confusion about the extent of police powers during the G20.

The government secretly passed a law in early June giving police the power to stop, search and detain anyone within five metres of the fence inside the G20 security zone.

However, police interpreted that as allowing them to stop and search anyone five metres outside the G20 fences, a mistake that wasn't cleared up until the summit was over.

NDP justice critic Peter Kormos said the whole situation calls out for a public inquiry. However, Premier Dalton McGuinty has refused to call one.

The Toronto Police Services Board will be conducting a review of G20 policing, and Andre Marin, Ontario's ombudsman, has also said he will investigate complaints about police behaviour during the summit.

With a report from CTV Toronto's Austin Delaney and files from The Canadian Press