Hannah Clarke's family speak out after car fire deaths

The family of the woman who was killed along with her three children in a Brisbane car fire have spoken out about the monster that's ruined their lives.

Hannah Clarke and her three children were set on fire by New Zealander Rowan Baxter on Wednesday. In a remarkably candid interview her family have spoken out about Baxter's controlling nature, and what lessons they hope others can learn from their tragedy. 

"These things happen to the most beautiful of people and this needs to stop," said Hannah's brother, Nathaniel.

It's the simple message the Clarke family is desperate to get across. 

"This is such a tragic event that hopefully nobody else has to go through we want to be able to help people in a similar situation that my sister was in." 

The family told Australia's A Current Affair programme that for years Hannah Clarke was manipulated and controlled by her husband, Rowan Baxter.

"She said to me 'I didn't think it was abuse because he never hit me'," mother Suzanne told A Current Affair.

From the outside they had the ideal life, three beautiful children, a successful CrossFit business and a loving relationship.

"He lived on social media, everything was to say he had the perfect family," Suzanne said.

But he had tormented her for years.

"They had to have sex every night and if she didn't he'd make the next day unbearable for the kids, once again not physically hurting the kids, but just make it a torturous day," said Nathaniel.

She fled the house in November to stay at her parents, which domestic violence experts say is the most dangerous time for women in her situation.

"She said to me only last week 'mum should I do a will? What happens to my babies if he kills me and he goes to jail for murder? Who gets my children?'," Suzanne said.

The reality was even more tragic.

On Wednesday, he ambushed her after she picked up their three children after school. 

He poured petrol through the car and set it on fire.

She managed to escape and survived long enough to give paramedics a detailed report of what he'd done, but she later died in hospital.

"To the end she fought to make sure that if he survived he got punished doing that to her babies, she was so brave," said Suzanne.

There has been an outpouring of grief across Australia, vigils have been held, and there are calls for more action to end the country's dreadful record of domestic violence.

"She fought for the children to the very end," the mother said.

"Everyone knows he was a monster but don't get caught up in the hate," said Nathaniel.