Nov. 21, 2013— -- Days after Brittany Murphy's father suggested she died from poisoning, her mother-in-law is demanding a full investigation into the actress' death and the death of her own son.
"They had everything to live for -- absolutely everything to live for -- and it was snatched away from them," Linda Monjack told ABC News.
"I do think something is wrong. It doesn't feel right. It doesn't sit right," Monjack said.
Monjack's son, Simon Monjack, who was married to Murphy, died just five months after the actress did, at the age of 40. Both died under similar circumstances, according to the Los Angeles Coroner.
The coroner ruled that the 32-year-old actress died in December 2009 of pneumonia, anemia and prescription drug intoxication. Monjack's autopsy showed the causes to be pneumonia and anemia.
"That to me would have alarm bells, but nobody seemed to take that up," Linda Monjack told ABC News.
But Angelo Bertolotti, Murphy's dad, has raised questions with a new toxicology report that he commissioned. Earlier this week, he made a stunning allegation to "Good Morning America."
"I absolutely positively think she was poisoned," he said. "I'm calling for her to be exhumed, if necessary."
Using samples of the star's hair, the Carlson Company, the lab commissioned by Bertolotti, said it found high levels of 10 heavy metals, according to the standards it said had been set by the World Health Organization (WHO), and suggested one possible explanation would be "an exposure to these metals (toxins) administered by a third party perpetrator with likely criminal intent."
However, the accuracy of those findings are now being questioned.
WHO, a U.N. agency that provides leadership in global health issues, said it does not establish reference ranges for chemicals in hair.
"The 'high values' for the chemicals listed in the Carlson Company report are from some other source, and not from WHO, and the laboratory should provide accurate citation for the source or sources of these values," WHO scientist Joanna Tempowski, who works in the organization's International Programme on Chemical Safety, told ABC News.
When the Carlson Company was asked to clarify the WHO standards it was citing, the Carlson Company manager Denny Seilheimer left ABCNews.com a voice message Wednesday saying they were referring to "the recommended high value established by the national World Health Organization. I hope I've answered your question. Have a good day."
Seilheimer could not be reached to clarifiy his reference to the national World Health Organization or the criticism that the use of hair samples was improper.
Two independent toxicologists dismissed Carlson's method of using hair samples after ABC News asked them to review the report. They said there are additional reasons that it's unlikely Murphy was poisoned.
Bruce Goldberger, a toxicologist who directs UF Health Forensic Medicine at the University of Florida and has seen Murphy's autopsy report, said the actress lacked the telltale sign of heavy metal poisoning when she died: lines across her fingernails.
"The bottom line is these hair test results cannot be used to support any allegation of poisoning, and cannot be used to establish a cause and manner of death," Goldberger told ABCNews.com.
Dr. David Lee, a toxicologist at North Shore University Hospital in Manhasset, N.Y., told ABC News that testing from hair samples is very difficult to interpret, since something as common as hair dye could have left behind heavy metals.
"You would actually need bodily fluids...tissues," Lee said.
The Los Angeles District Attorney's Office told ABC News that it's not investigating these new allegations, but the coroner's office said it's willing to take a look at Carlson Company's toxicology report once it receives a copy.
"I just hope that it all comes to something in the end and that justice is served," Linda Monjack told ABC News.