The biological mother of a four-month-old child who died in foster care in April says she'll likely have to sue the province to get answers to what happened to her daughter.

And critics say the case highlights Alberta's secretive — 'cover your mistakes' — system of investigating deaths of children in foster care.

"I'm angry and I'm frustrated... at least if there was an external investigation done, at least then people could actually find out what's going on and what happened and get some kind of answers," said the Warburg mother who can't be identified because of a provincial law banning the publication of the identity of children in foster care.

The mother says social workers and police apprehended her child when they showed up to take away her roommate's two children.

An affidavit by one of the social workers claims the mother "appears to suffer from an alcohol addiction."

The mother rejects she's a drinker, stressing her child was happy and healthy before being taken away.

Six children died while in provincial care last year.

Questions left unanswered: critics

Critics argue Children and Youth Service's internal reviews of deaths of children in provincial care leave many questions unanswered.

The government says its in-house investigations "promote continuous improvement and learning opportunities," while protecting the privacy of children and the families involved.

A public fatality inquiry is required by law into all suspicious deaths of children in provincial care.

But the head of Edmonton's Metis Child Family Services Society disputes the utility and transparency of internal reviews.

Donald Langford has sat on three internal reviews in the last decade.

"I do think, you know, the first reaction is to cover your ass," he said.

"I thought there was often maybe a hesitancy or unwillingness to point out responsibility or a lack of responsibility and sometimes to point out inconsistencies in case management practices or maybe a bit of a lack of, say, proper work ethic. I found a lot of that stuff was overlooked," added Langford.

In British Columbia, the arms-length Representative for Children and Youth receives immediate notification of serious injury or death of children in provincial care.

The advocate does an initial review to determine if there is a need for a formal review.

Sarvia Elizabeth Velasquez, who died last May at just 14 months old, was killed, police said in May. Family photoThe opposition NDP blasted Children and Family Services recently for the way it investigates children who die in provincial care, calling the ministry either "tremendously incompetent or dangerously secretive."

"I think that the province's mantra about privacy is simply self-interested exploitation of the concept. It is absolutely possible to engage in meaningful, detailed transparent reviews, while maintaining the privacy of the individuals involved, but at the same time ensuring that the public has enough information to truly hold the government accountable," said NDP MLA Rachel Notley.

Alberta's minister of Children and Youth Services tells CBC News the province might start conducting external, independent reviews of all children who die while in provincial care.

In May, Yvonne Fritz took the unprecedented move of ordering a panel of independent experts to investigate the suspicious death of 14-month old Calgary child Elizabeth Velasquez.

Police say the girl died in May of 2010 while being cared for by her mother and her boyfriend.

Her father and grandparents had asked social services to intervene before her death.

Fritz says she will "absolutely" consider launching external reviews of all deaths of children in provincial care if the recommendations of the panel reviewing Velsquez's death "lead to greater safety and protection of our children."

"You'd better believe that we'd continue with that process," said Fritz.

The panel of experts drawn from public health, social work and law enforcement is expected to issue its public report in about six weeks.

With files from the CBC's Trisha Estabrooks