A father who murdered his estranged wife and three young children breached a domestic violence order weeks before he committed quadruple murder-suicide.

Rowan Baxter was due to face court again on April 8 after a magistrate ruled he was free to walk free in the community during his initial hearing for breaching the order on January 29.

On Wednesday morning, Baxter torched his family car while his three children, six-year-old Aaliyah, Laianah, four, and Trey, three, were trapped in the back seat at Camp Hill in Brisbane’s east.

Queensland Police were previously called to a family violence incident that involved the couple just last month.

Ms Clarke made the decision to separate with Baxter in December, and quietly moved her children out of the family home and in with her parents in Raven Street, in Brisbane’s Camp Hill.

Baxter was occasionally allowed to see the children on weekends, but there was always tension and even one assault on drop offs and pickups.

‘He kidnapped (one of the kids) on Boxing Day and took her interstate for four days until the police got her back,’ Ms Clarke’s mother told Daily Mail Australia.

Ms Clarke told a friend of the incident in a text message, saying she’d taken out a domestic violence order against her husband.

Detective Inspector Mark Thompson said both Ms Clarke and her estranged husband had been referred to support services in the lead-up to their deaths.

‘When it comes to Hannah, we have dealt with her on a number of occasions, we have ­actively worked with the Brisbane Domestic Violence Centre in supporting Hannah throughout her family issues,’ he said.

Ms Clarke’s father said Baxter was ‘under orders’ to remain at least 20 metres away from her.

‘We still don’t know how he got so close,’ he said. ‘He’s obviously ambushed her somehow, I’m sure she would not have stopped for him, she would be more likely to try to run over him.’

He was going through her phone and tracking her whereabouts. It was really scary,’ Ms Clarke’s mother added.

‘He thought he was hard done by and wanted 50 per cent of custody and we knew that couldn’t work, the guy didn’t work, he couldn’t support his own family. It started getting ugly.’

Three weeks ago – the last time the children stayed with Baxter at the former family home 3km away – he and Hannah got into an argument as he dropped them off.

The Clarke’s said Baxter assaulted Hannah in their front yard by grabbing her by the wrist and twisting her arm behind her back, hurting her shoulder.

He was charged with assault.

The couple were together 11 years before the separation, but Ms Clarke’s brother Nat confessed her family were desperate to get her to leave.

‘My mum and dad… have given every little thing they own to help my sister try and get away from this monster,’ he wrote on Facebook.

‘Yesterday I had my sister, nephew and two nieces taken from me in the worst way possible by a heartless monster they called their dad.’

He added: ‘Everyone who has been lucky enough to be a part of their lives would know just how sweet and loving these kids and my sister really were.’

Right before she died, Ms Clarke expressed her excitement for the year ahead.

She was going about her morning and had just strapped her kids into their child seats in the back of the car when Baxter dived in and doused them all with petrol.

He set the car alight, but both he and Ms Clarke managed to free themselves.

Ms Clarke repeatedly screamed for someone to save her babies – even as her skin was melting off her body from the flames – while Baxter tried his hardest to stop any bystanders from helping his children.

Once he realised they weren’t escaping the car alive, he stabbed himself in the chest.