In a case that a prominent Canadian civil-rights lawyer says could have a chilling effect on free speech, Ottawa is taking a group of animal-rights activists to court for coming too close to a sealer while filming the hunt.

The five activists face charges in Quebec for allegedly violating federal marine mammal rules that restrict coming within 10 metres of seal hunters.

Federal prosecutors have already dropped an earlier charge accusing them of obstructing the hunt.

The defendants — all of whom are with the Humane Society of the United States or the Humane Society International — appeared Thursday in a courtroom on Isles de la Madeleine in the Gulf of St. Lawrence.

They have all pleaded not guilty.

After having dropped the charge of interfering with the hunt, the remaining charge carries a maximum fine of $100,000.

Ruby, one of Canada's most prominent defence lawyers, is acting as counsel for the activists.

The five were recording the controversial March 2006 seal hunt in the southern Gulf, near the Cape Breton coast, hoping to capture images of animal cruelty for a campaign to stop the slaughter of seals, he said.

Clayton believes Ottawa is attempting to restrict the rights of his clients.

"It really is about whether the government can continue to keep people from getting photographic images and putting them around the world so that the whole world knows what we do," Ruby told the Canadian Press in an interview.

The Marine Mammal Regulations outlining the 10-metre buffer around sealers is not meant to be a "restriction on observation," Fisheries Department spokesman Phil Jenkins said.

The government continues to hand out observer permits annually during the mid-March seal hunting season, he added.

The defendants are Canadians Rebecca Aldworth and Andrew Plumbly, Americans Chad Sisneros and Pierre Grzybowski and British citizen Mark Glover.

In a news release, Humane Society International said Wednesday the charges "are part of an effort by the Canadian government to close the curtain on this gruesome enterprise."

With files from the Canadian Press