Father Angelo Bertolotti, 87, claims Brittany and her husband were killed for supporting Department of Homeland Security whistleblower
Julia Davis claimed U.S. was letting in terrorists over the Mexican border because of lax security and her backers were put under surveillance
She and Mr Bertolotti are writing a tell-all book on the mystery
The Clueless actress died on December 20, 2009 and the Los Angeles County Coroner said at the time it was due to pneumonia
Husband Simon Monjack died five weeks later in the same house
A new toxicology report ordered by her father found ten heavy metals in the actress' system, meaning she might have ingested rat poisoning
Angelo Bertolotti, 87, alleges that at the time of her death his daughter was under surveillance from shadowy government operators who wiretapped her phone and terrorized her after she spoke out in support of a Department of Homeland Security whistleblower.
Julia Davis, who claims to have once worked as a stunt double for Angelina Jolie, says Brittany was being persecuted for standing up for her.
Davis claimed she was branded a ‘domestic terrorist’ after she exposed security flaws that were allowing terrorists to sneak into the U.S. while she was working as a border security guard in California.
The extraordinary claims are what drove Brittany’s father to campaign to have a separate toxicology test conducted on the star.
The new report found rat poison may have caused the shock death - in stark contrast to the official coroner's report that concluded it was natural causes.
The latest twist to the growing mystery over the actress’s death came as relatives called on police in Los Angeles to re-open the investigation.
‘I called it two weeks after it happened,’ one family member told MailOnline. ‘You just don’t have two people die like that under those circumstances.’
Officials insist there is no evidence to support a more sinister motive behind 32-year-old Brittany’s sudden death in the bathroom of her Los Angeles home on December 20, 2009.
Discover more about Top Priority: The Terror Within
'Poison': Ms David revealed independent toxicology tests had found that Brittany had ten times the safe WHO levels of some heavy metals in her body - chemicals commonly found in rat poison or bug killer
Her husband, British screenwriter Simon Monjack, 40, died in similar circumstances five months later.
The Los Angeles coroner ruled the deaths were due to pneumonia and anemia. Health officials later reportedly suggested toxic mold in the house could have played a role in the tragedy.
But the actress’s father is steadfast in his belief foul play was behind the mysterious deaths and launched a lawsuit last year demanding the release of hair samples from Brittany’s body to carry out the new tests.
Although the legal action – which named arsenic as a possible cause of death – was dismissed, the father was given hair, blood and tissue samples to carry out the independent laboratory tests.
In a report for Examiner.com, Ms Davis wrote that scientists at independent Carlson Company laboratories found ten heavy metals in Brittany's system which were several times higher than World Health Organization high levels at the time of her death.
'If we were to eliminate the possibility of a simultaneous accidental heavy metals exposure to the sample donor then the only logical explanation would be an exposure to these metals (toxins) administered by a third party perpetrator with likely criminal intent,' the report says.
Brittany Murphy did NOT die from natural causes and may have been killed with RAT POISON, claims shocking report
Heavy metals are found in most rodenticides and insecticides meaning the actress could have been slipped rat poisoning or bug killer.
At the time of her death, Brittany displayed all the symptoms of heavy metal poisoning including: headaches, dizziness, abdominal cramps, coughing, sweating, disorientation, wheezing, congestion and pneumonia.
Mr Monjack also exhibited similar symptoms before his death, leading some to believe he too was poisoned.
Conspiracy: Davis claims in a YouTube video that her supporters were followed by Blackhawk helicopters, wiretapped, and that Brittany was afraid to go home because of 'sneak-and-peek excursions' on their home
Stormed: Ms Davis posts footage in the YouTube video of her documentary 'Top Priority: Terror Within' of what she claims is a raid on her home by agents costing taxpayers thousands of dollars
His mother-in-law Sharon discovered his body after moving in with him following her daughter's death.
In a recent interview with Los Angeles-based Fleur De Lis Film Studios, Mr Bertolotti said: ‘They were, in fact, under surveillance, including helicopters. Their telephones were wiretapped, Brittany was afraid to go home, because of the sneak-and-peek incursions into their residence and other terror tactics she suffered after speaking out in support of Julia Davis and being named as a witness in her lawsuit against the Department of Homeland Security.’
At the time of her death, early speculation was that the actress died of a drug overdose or anorexia after years of shocking weight loss.
Prescription pills were found in the actress' system, but they were treating a cold and respiratory infection.
Mr Bertolotti and Ms Davis are writing a book, ‘Britt’ detailing what they really believe happened to the star and a documentary, ‘The Terror Within’, which has not yet been released.
Ms Davis claimed that while working at the US border with Mexico she uncovered evidence that dozens of potential terrorists had entered America in shady circumstances that may have involved the bribery of customs officials.
Campaign: Mr Bertolotti is writing a book with Ms Davis on the mystery. A family member told MailOnline: 'You just don’t have two people die like that under those circumstances'
On a whistleblower website, Ms Davis wrote that family members and witnesses who dared to support her were ‘subjected to land and aerial surveillance, to the tune of millions – at the expense of American taxpayers.
‘This included warrantless aerial surveillance with fixed-wing airplanes and Blackhawk helicopters, vehicular surveillance, OnStar tracking, Internet monitoring, wiretaps, warrantless searches and seizures and series of other outrageous, unwarranted retaliatory measures.’
On the National Whistleblower Center website, Julia Davis said she 'prevailed' in court against the Department of Homeland Security despite a total of 54 'retaliatory' investigations being launched against her in an 'attempt to discredit Julia as an upstanding law enforcement officer and a staunch American patriot.'
On the site, she says that when her fears about terrorists being able to slip into the U.S. were ignored by her bosses she went to the FBI, infuriating her bosses.
Last year, a trailer for the documentary about the whistleblower case, called 'Top Priority: The Terror Within,' was posted on YouTube.
It features photos of Angelo Bertolotti with his daughter and visiting her grave. He also says that Brittany 'was called as a witness in the Julia Davis case.' He added: 'Brittany did tell me she was under surveillance and incidentally so was I.'
The video claimed Miss Murphy and her husband were subjected to the same 'terror tactics' as Ms Davis.
The video also featured footage of a Blackhawk helicopter raid on Ms Davis's Yucca Valley, California, house.
Ms Davis says in her blog that a judge sided with her to rule the 2005 raid on her home was an 'abuse of process.'
Miss Murphy was perhaps most famous for her role in 1995's Clueless, but she also had more serious roles in Girl, Interrupted and played Eminem's love interest in 8 Mile - the movie about the rapper's life.
At the time of her death, Miss Murphy's career had tapered off and her last major role was in 2004's Little Black Book.
Before marrying Mr Monjack, the actress dated Ashton Kutcher, her co-star in the film Just Married.
After breaking up with the actor, she went on to have two serious relationships that led to engagements with talent manager Jeff Kwantinetz and production assistant Joe Macaluso before marrying Mr Monjack, a screenwriter, in May 2007.
Brittany Murphy¿s Father Sets the Record Straight
Brittany Murphy did not die of natural causes, lab report shows