Alberta opposition parties called for a public inquiry into the deaths of children in provincial care on Monday after a media report concluded the government has been under-reporting the numbers.

A lengthy investigation by the Edmonton Journal concluded a total of 145 children died while in care since 1999 but the province only reported 56.

The report prompted both the Wildrose and Liberal parties to call for a public inquiry; the Alberta NDP wants the child advocate to publicly review the death of every child in care.

Wildrose leader Danielle Smith says an inquiry should be held so the public can hear what went wrong. 

"We need to go through and have a public inquiry so we can find out what the real, actual number of deaths were, any of the recommendations that were related to those deaths and track whether or not it's been implemented and understand what's gone wrong with this system," she said. 

The number of child deaths was the main topic in question period on Monday. 

"To the premier, even today you only report child deaths in care and not child deaths in protective services," said Edmonton NDP MLA Rachel Notley. "How can Albertans possibly trust you?"

Liberal leader Raj Sherman also directed his questions to Redford. 

"Why is your government trying to cover up the deaths of 145 children?" he asked. 

A request by the opposition to hold an emergency debate on the deaths was rejected by Speaker Gene Zwozdesky. 

Human Services Minister Dave Hancock says the discrepancy in the numbers comes from how deaths were reported. 

"What wasn't reported before were children who died of natural causes, of medical causes, or accidental deaths," Hancock said.

"They still would have been reported to the medical examiner's office and the medical examiner's office would have determined whether or not there was a need to move forward. But those were the ones that were not included in the public annual reports of the department."

Hancock says all deaths have been reported since new legislation was passed last year.

'Blanket statement that means nothing"

Velvet Martin, the St. Albert mother whose disabled 13-year-old daughter Samantha died after spending most of her life in foster care, says she's heard the same response from Hancock's predecessors. 

Velvet Martin

Velvet Martin's disabled daughter Samantha died in December 2006 after spending most of her life in foster care. (CBC )

“That was the same reaction that was told to the public by [Janis] Tarchuk, by [Yvonne] Fritz, by every other minister that has gone before Dave Hancock and I’m sorry but that’s just not acceptable," Martin said. 

"It’s just a blanket statement that means nothing. Not to us who have lost our children’s lives.”

Samantha Martin was born with a chromosomal abnormality called Tetrasomy 18p. Her parents placed her in foster care on the advice of Alberta Childrens' Services. 

Martin was malnourished when she died and went for long periods of time without seeing a doctor. A social worker was supposed to see her every three months but sometimes 14 months would go by without a visit. 

A fatality inquiry last year found that the system failed the young girl

Velvet Martin had to go to court for the right to publicly discuss her daughter's experience in the foster care system. Alberta legislation prohibits the identification of anyone under the care of Childrens' Services and Martin believes these publication bans need to end. 

Sevenn years after Samantha died, Martin says the loss is still very hard on her family.

“People are forever changed … you live like this for the rest of your life in a state of loss," she said. 

The Journal's investigation followed a four-year legal fight with the province to get access to records under freedom of information laws.

The report lists youngsters who have died by hanging, malnutrition, hypothermia, head trauma, drowning and disease.

With files from The Canadian Press