Brittany Murphy.

Brittany Murphy. Photo: Getty

In an open letter to The Hollywood Reporter, Brittany Murphy's mother has slammed claims her daughter was poisoned.

Last week, Murphy's biological father released the results of new laboratory tests suggesting that Murphy and her husband, Simon Monjack may have been killed with rat poison. This was contrary to original coroner reports stating that the two were killed by pneumonia and anaemia.

In response, Sharon Murphy, who has up until now "chosen to stay out of the limelight" has decided to speak up.

"I have no choice now but to come forward in the face of inexcusable efforts to smear my daughter's memory by a man who may be her biological father but was never a real father to her in her lifetime.

"Angelo Bertolotti has relocated to California in his old age to claim he is here for Brittany, as he never was in life. He has made outrageous statements over the past few years, culminating in this latest madness: that my darling daughter was murdered."

Sharon says that she raised Brittany on her own, pointing out that Bertolotti, who spent 12 years in prison, only came "out of the woodwork" when their daughter began to find fame.

"It sends pain through my heart when I read [in recent reports about Bertolotti's lab testing results] that 'the family said' - meaning Angelo - because he was never her family in reality. "

She also believes that Bertolotti, who has started up the Brittany Murphy Foundation and apparently has plans to write a book and make a documentary about his daughter, had the lab tests done for publicity.

"The lab Angelo used, if you can call it that, is an internet site that farmed out the actual testing and then wrote horribly untrue things under the guise of 'analysis.' It mentioned rat poison as a possible cause and claimed to be able to say that a third party murdered my beloved daughter ...

"If she had, don't you think it would have shown up in the coroner's test of her blood and tissue?"

Sharon, who as a result of the new tests sought the advice of experts, says that the samples Bertolotti had access to were not enough to make a convincing argument.

"A hair sample can be affected by many outside factors, including hair dye, hairspray, prescription medications, foods, smoking the occasional cigarette and environmental factors," Sharon writes. "One cause we now know may have been toxic mould that was eventually discovered in that house - which may have been what really killed her.

"We will never know for sure. However, we do know the Los Angeles County Coroner did extensive tests and found that she died of natural causes. And now she is a real living angel in heaven."

Fairfax Media