A woman accused of binding her elderly father in cling wrap and suffocating him with a pillow believed he was a "demon" and he "had to go", a court has been told.

Ederino Beltrame, 70, died in April 2001 with a doctor signing off his death as from natural causes.

He had been suffering a terminal heart condition and was hospitalised with a brain haemorrhage in the months before his death.

An inquest into Mr Beltrame's death was terminated last year after his granddaughter and primary carer, Romina, came forward to accuse her mother, Daniella, of his murder.

Daniella Beltrame has pleaded not guilty to murder, forging her father's will and intimidating her second daughter, Loretta, to prevent her from giving evidence at the inquest.

Opening committal proceedings against Beltrame today in Sydney's Central Local Court, prosecutor Stephen Higgins, SC, said relations between Beltrame and her father were "strained" for some years and arguments had escalated into violence.

"In the early hours of the 26th of April, 2001 [Romina] was woken by her mother, the defendant, calling her from her grandfather's room to come and help," Mr Higgins told the court.

"When she entered the room she saw her grandfather bound to the bed with [cling wrap] and her mother forcing a pillow onto his face.

"After a struggle Romina was forced from the room.

"Her mother [followed] a short time later and told her that her grandfather was a demon and that he had to go.

"When she woke the next morning her grandfather was dead."

Beltrame produced a will in the days following her father's death which left her his entire estate.

Subsequent examinations of the document revealed his signature had been forged and typewriter ribbon seized from Beltrame had been used to make it, Mr Higgins said.

Analysis of Beltrame's computer hard-drive showed she had accessed internet sites relating to the detection and penalties for forgery and document examination.

She also had searched sites on death by poisoning, lethal injection, oxygen deprivation and air embolism, he said.

Beltrame allegedly approached her daughter, Loretta, prior to the inquest and demanded she not give evidence against her.

"The defendant presented documents which she demanded Loretta sign," Mr Higgins said.

"Loretta only looked at one of these documents which stated that she, Loretta, had wanted to kill her grandfather."

Doctor did not examine man

Mr Beltrame's doctor Syed Khamaruz Zaman today told the court the 70-year-old had been suffering from a terminal heart condition and was admitted to hospital with a brain haemorrhage months before he died.

Dr Zaman said he signed Mr Beltrame's death certificate without examining the man because he presumed he had died from natural causes.

"He had severe cardiac failure in the terminal stage," Dr Zaman told the court.

"I was not surprised [to hear of his death] because I knew it was going to happen and I was expecting the call any time.

"I did not examine him because I had known the patient's condition and the way he was sinking, I took it for granted ... that it was a matter of time."

The doctor said he saw no signs of injury or anything to rouse suspicion when he briefly looked Mr Beltrame over before signing the certificate.

Beltrame's lawyer John Stratton, SC, showed the doctor a photograph of an injury to Mr Beltrame's arm resembling bite marks or scratches with bruising.

The doctor said he didn't recall ever seeing such an injury.

"Had you been informed that there had been an episode of violence prior to Mr Beltrame's death, would you have issued the death certificate?" Mr Stratton asked.

"No," Dr Zaman replied.

"I didn't suspect anything, I knew that he was dying of natural causes.

"But if there was anything [suspicious] ... I would examine the body in detail."

Forensic pathologist Dianne Little said Mr Beltrame could have been smothered or died of natural causes.

Binding with cling wrap could have left no restraint injury to the body and suffocation could leave only minor bruising to the lining of the eyes and mouth, she said.

"If someone is presented as a heart attack, [authorities] may not look for subtle injuries," Dr Little said.

Forensic specialist Anthony Moynham agreed it was impossible to say whether or not Mr Beltrame had died of natural causes.

"It wouldn't be the situation where I would say that he was close to death, but certainly his health was deteriorating," Dr Moynham said.

"Every day he is going to be a bit worse but how much worse it is hard to say.

"I can't really rule out natural causes at all."

Wearing a green shirt and black skirt, Beltrame sat impassively in the dock.

The hearing continues.

AAP