Three more plaintiffs have been added to a proposed class-action lawsuit alleging physical and sexual abuse of students at the Alberta School for the Deaf in Edmonton between 1955 and 1996, when it was run by the province.

The statement of claim filed Tuesday alleges that some students who attended the boarding school during that time were slapped, caned, choked and hit with objects while others were sexually abused.

The school was funded and operated by the Alberta government until the fall of 1995, when it was taken over by Edmonton Public Schools. The school's current administration is not named in the lawsuit.

The class action has yet to be certified.

The papers filed in court allege that because students were rarely allowed to go home during the school year, they had no chance to seek help from their families.

They were also forced to communicate verbally rather than through sign language, which made it difficult for them to report the alleged abuse, said lawyer Tony Merchant, who filed the recent claim.

"They weren't allowed to use American sign language, which made them perfect victims," Merchant said.

The claim filed Tuesday was made on behalf of two female former students, who allege they were sexually abused by staff members and by older male students, and a male former student, who alleges he was physically abused by staff.

Abuse a 'systemic problem,' lawyer alleges

In an interview with CBC News, Merchant said he felt the two women should get damages of between $500,000 to $1 million from the Alberta government.

"It became a systemic problem, and it also led to huge problems in terms of abuse physically and an abysmal graduation rate where people weren't getting out of the schools what they were intended to get — namely, a Grade 12 education," he alleged.

Merchant's firm first filed two statements of claim in 2004 on behalf of 80 plaintiffs, claming abuse at the Edmonton school between 1955 and 1983, said Kathy Telfer, spokeswoman for Alberta Education. The province filed a statement of defence at the time, she said, but has not yet been served with this latest claim.

Since the original claims in 2004, Merchant said, the firm has received calls from other former students of the Edmonton school as well as of other schools for the deaf across Canada alleging abuse. He said that rather than pursuing individual claims, he hopes to expand the Edmonton lawsuit to a national class-action case.

The lawyer said he's heard from former students in Manitoba and hopes to file a class action lawsuit in that province in five or six weeks.