Brittany Murphy's dad refuses to give up death investigation

Brittany Murphy's father has vowed to continue fighting Los Angeles authorities to get to the bottom of his daughter's tragic death, three years after her passing.

Angelo Bertolotti is not satisfied by the outcome of toxicology results which suggested the Clueless star's 2009 death was the result of pneumonia, anaemia and excessive use of prescription medications.

He filed suit against the Los Angeles Police Department and the Los Angeles Coroner's Office at the start of this year (12), asking the officials to re-open the investigation into her demise at the age of 32.

Bertolotti, who was estranged from his daughter for much of her adult life, asked authorities to release Murphy's hair and tissue samples so they could be independently tested for toxic substances, poisons and heavy metals.

The request was initially granted but Murphy's dad was subsequently told they could not release the specimens - and he can't understand why.

He says, "I'm in disbelief that my simple request would turn into such an ordeal."

However, Bertolotti is refusing to give up the fight, despite encountering so many setbacks - and he recently hired George G. Braunstein - the same lawyer handling the investigation into the death of Sylvester Stallone's son Sage - to take up the case.

He adds, "Whether it exposes incompetence or corruption, I will continue moving forward to find out what truly caused Brittany's death."

Murphy died three years ago on Thursday (20Dec12).