The biological mother of a 21-month-old girl who died Wednesday while in the care of foster parents, says her daughter was murdered and was wrongfully placed in the foster care system.

The mother, who cannot be named, believes her daughter was unjustly taken from her and adds that she was working with a lawyer to get custody of her daughter.

"Someone murdered my daughter," she said in a statement to CTV News. "I have other children in my care. I am standing here looking at my son."

She says her daughter was under a temporary guardianship order for three months, but insists she never signed the papers.

"I was going to court on March 8 to get her back. She was not supposed to be in the foster care system," said the mother. "Something is wrong with the system."

The mother goes on to say that her family has a good home and that she had the support of her family members.

The province has released few details about the case, but says it is investigating what happened, how it screened the foster parents and how it monitored the child.

Opposition members are now calling for a public inquiry, saying the death illustrates a broken system.

"There are just too many fatalities in the system and I think very clearly we need the public to get the full story here," said Alberta Liberal Kevin Taft. 

Police have not released the child's cause of death, but they are investigating it as a homicide.

Biological family members believe it may have been a case of shaken-baby syndrome.

They say the little girl suffered severe brain damage, and that doctors told them the toddler may have been shaken to death.

The 21-month-old girl was in the care of a Morinville-area foster family when she died at the Stollery Children's hospital Wednesday, two days after she had been admitted.

The little girl's family released a statement saying, "What we know is that the baby was brought to the Stollery on Monday, March 1st and was in a coma. After two days, the baby succumbed to her injuries with her family at her side."

The death comes two weeks after the Minister of Children and Youth Services met with foster-care workers to discuss some of the challenges they face. 

Janet Ryan-Newell, the executive directive of Crossroads Family Services, a non-profit organization that provides foster care for children in the Edmonton area, says she was sad to hear about the death, but suggests the tragic story overshadows what she believes to be the wonderful work foster families do.

"Every month, thousands of successes -- they never hit the news and they can't, so it is very frustrating," she said.

Privacy laws prevent foster parents from sharing their successes, until the child is an adult.

She also goes on to say that in her opinion the bigger problem is a lack of funding for foster families.

"What's broken in the system is what's broken in every system and that is limited funding and trying to fix things retroactively instead of proactively," said Newell. 

A memorial service for the child will be held on Tuesday.