Montreal police have found the remains of a girl who disappeared 12 years ago and say they are pursuing a "serious lead" in the cold case that rattled the city's Pointe-Saint-Charles neighbourhood.

Montreal's major crimes squad said Jolène Riendeau's disappearance in 1999 is now being treated as a homicide.

But police are not disclosing any information, including where the body was found or in what circumstances, because they are closing in on a suspect.

"For the past 12 years, we met so many witnesses and suspects, and no one has been accused so far," said Sgt. Ian Lafrenière. "Now we got a serious lead, and we'll do everything possible to accuse someone."

Riendeau's mother Dolores Soucy has held out hope for years that her daughter would be found alive.

Her family was called into Montreal police headquarters Wednesday morning.

"It was devastating news for the family, who were clinging to the hope that their daughter was still alive today," said Pina Arcamone, director of Quebec's Missing Children's Network, who accompanied the family to the police station.

Joanne Grenier's daughter was friends with Riendeau. (CBC)I think they are still in shock," Arcamone said.

Riendeau was 10 on April 12, 1999, when she was last seen outside a convenience store six blocks from her home, where she went to buy a bag of potato chips.

She had skated over to the dépanneur on her rollerblades just before supper, and never came home.

Store owner Jean-François Marcoux said the case has haunted the neighbourhood ever since.

"As soon as you say the name Jolène Riendeau, everyone knows what you're talking about."

'It was devastating news for the family, who were clinging to the hope that their daughter was still alive today.' —Pina Arcamone, Quebec Missing Children's Network

Joanne Grenier, a Pointe resident, said one of her daughters was good friends with Jolène, who was supposed to come over to their house on the night of her disappearance to have some birthday cake.

"I thought we'd see her again," said Grenier. "My daughter can't believe it."

Community organizations and neighbours had joined in the search for the girl. Posters of Riendeau were plastered across the province in the effort to find her.

Police followed up on more than 1,500 tips and interviewed several suspects and witnesses over the years.

In May 2005, one of those tips led Montreal police to search a section of the Lachine Canal near the Charlevoix Bridge. The search did not turn up any results.

Retired Montreal police detective André Bouchard worked the Riendeau case for years, and has mixed feelings about Wednesday's news.

"I'm proud of the guys who worked the case, but I'm also sad for the family, because that little, little thing we had in our hearts, that she might not be dead.… well, she is dead."

Police searched the waters of Montreal's Lachine Canal in May 2005, looking for the body of Jolène Riendeau. (Paul Chiasson/Canadian Press)Jolène would have turned 23 this August. Her parents, now grandparents, left Pointe-Saint-Charles to live in Montreal's east-end Tétreaultville neighbourhood.

Senator Pierre-Hugues Boisvenu, a staunch advocate for victims' families, said he hopes the Riendeau family can start mourning.

"Twelve years without an answer on a child's disappearance, whom you think, whom you hope is still alive — it's the worst situation that a father or mother can experience," he said.

"All we hope for now is to find who did it. An unsolved murder means a recidivist is still roaming the streets."

With files from The Canadian Press, Kristin Falcao