BRISBANE’S “house of horrors” grandmother tried three times to kill her 11-year-old step-grandson – once in a fire and twice by suffocating him in his bed, police will allege.

The 58-year-old Caboolture woman will face court today charged with four counts of attempted murder, attempted arson and interfering with a corpse.

Police this month revealed they were investigating the deaths of two boys, one aged three years and the other seven months, at the Morayfield home, as well as the attempted murder of two boys, aged 11 and nine, in a fire.

WARNINGS IGNORED: Children not separated

Police will allege the 11-year-old boy woke on two separate occasions to the grandmother trying to smother him in his bed. They will claim she used a pillow and a tea towel in her attempts to murder the boy.

They said both deaths and the fire occurred when the grandmother was at the house.

It is understood investigators will rely on the boy’s version of events – a version denied by the grandmother.

media_camera Eleven year old boy involved in the incident.

Detectives yesterday confirmed they were continuing their investigations into the suspected murders of the two younger children – one being the woman’s seven-month-old grandson.

“Today is one step, there are still further steps to be taken in the investigation, so today is just one step,” Detective Acting Inspector Ben Fadian said.

The Courier-Mail can reveal police charged the woman with interfering with a corpse under the belief she lied about how and where the youngest boy died.

Police renewed their investigation into the death of the three-year-old boy, who died in July 2013 from a suspected infection, following a fire at the family’s Morayfield home on February 27.

The two older boys claimed to have been trapped inside their bedroom during a fire that broke out when they were being cared for by their grandmother. Police enlisted the help of the fire brigade to recreate the fire in an effort to determine why the boys had been unable to escape from the bedroom.

“Investigations to date show the children’s escape from the bedroom was intentionally impeded,” police said.

media_camera The seven-month-old baby who died with his grandmother and his father.

The father of the two older boys said he was horrified to learn the woman had been charged with attempting to murder one of his sons on three occasions.

“No one has called me,” he said. “I have no contact details for them (the boys). It’s pretty bad.”

The three-year-old boy died on July 27 after suffering flu-like symptoms. He was taken to hospital but went into cardiac arrest.

On September 27, seven months after the fire, the children’s mother found the baby boy dead in his cot.

media_camera The baby’s father at the gate to the property yesterday.

The grandmother is believed to have told police she put the child to bed with a bottle the night before and got up at 2am to check on him after hearing him stir.

She said she woke at 7am to the sounds of the boy’s mother “screaming hysterically”.

The boy’s father said this month that he believed his mother was not capable of killing “anything”.

He said he woke one morning to the news his son was dead.

Yesterday, the man walked out of his house carrying a sign with the words “private property no entry”, saying he would expose “lies” and “corruption” in the case.

Police yesterday questioned the children’s mother about whether she had taken steps to protect the children.

Solicitor Tim Meehan, from Bosscher Lawyers, said the grandmother was “assisting police”.

Additional reporting Chris McMahon and Trenton Akers

Memories of laughter where there are children no more

NESTLED among stands of trees and tropical palms, at the end of a winding drive, is Brisbane’s “house of horrors”.

It’s a place where boys once laughed and played. Where a large block of garden provided endless room to run and chase. But there were no children behind the wire fence of the Morayfield home yesterday – the home where police suspect two children were murdered and another two locked in a fire.

It was once home to the children’s grandmother. Police say she was there when the three-year-old boy died.

She was there when a fire broke out inside the house, threatening two boys in their beds. And she was there when the youngest – an infant of seven months – died at night.

She was the last to see both boys alive and the only adult home when the fire started.

The woman’s son – and the father of the youngest boy – walked the neglected yard to place a sign at the property’s front gate. He said he would expose “lies” and “corruption” in the case.

In a previous interview, the man said his mother was a beautiful kind-hearted person.

“I highly believe my mother would not be capable of killing anything,” he said. “Why would she all of a sudden? She is still the same person from 20 years ago.”

The sign he held yesterday – “private property no entry” – warned media to keep away. It was a repeat of an earlier warning when a visitor threatened to assault journalists waiting in the street.

The home’s four bedrooms are no longer home to those who played and slept there. Two little boys are dead. Two older boys are now in a “safe house”.

The Courier-Mail was once invited inside, viewing the small room where the fire took hold. There was no sign of the flames the family claimed began when someone threw an object through the window.

The grandmother has denied any wrongdoing – both with the fire and the deaths of the two boys.