Brittany Murphy's cause of death has come into question after new toxicology results allegedly suggest she may have been poisoned.

The '8 Mile' actress was found dead at home in 2009 and the Los Angeles Coroner ruled her death was accidental, caused by pneumonia and ''iron deficiency anemia.''

Five months later, the 32-year-old star's husband Simon Monjack, 40, also died of pneumonia and anemia.

Brittany's father Angelo Bertolotti wasn't convinced by the coroner's findings and The Huffington Post claims he ordered a new toxicology report after sending samples of his daughter's hair for independent analysis.

Results supposedly showed the presence of 10 heavy metals above the ''high'' level set by the World Health Organisation.

The types of metals are commonly found in rat poison, pesticides and insecticides.

Angelo reportedly tried to sue the Los Angeles Police Department and Los Angeles Coroner's Office, accusing them of ''failure to conduct toxicology tests'' on specimens of hair and his daughter's death was ''incorrectly determined to have been allegedly caused by pneumonia and anemia.''

It has been reported the lawsuit was dismissed but Angelo secured the release of Brittany's hair, blood and tissues for testing which he sent samples of to the Carlson Company in Colorado for independent analysis.

Julia Davis, a screenwriter who worked for the U.S. Department of Homeland Security, began working on a biography of Brittany and is said to have sent an email to The Huffington Post today (18.11.13) saying she has sent formal requests to authorities ''demanding'' the deaths be ''properly'' investigated based on the new findings.

Angelo and the Los Angeles Country Coroner are yet to comment.