Hannah Clarke inquest: New Zealand-born killer dad Rohan Baxter's note found on his phone

Rowan Baxter killed Hannah Clarke and her three children. Photo / Supplied

Killer ex-husband Rowan Baxter wrote a threatening note to his ex-wife shortly before he burned her and the couple's three children to death.

A Queensland coroner's court was told of the note as part of an inquiry into the horrific February 2020 murders.

In the letter, New Zealand-born Baxter attempted to paint himself as a victim and accused Hannah Clarke of "destroying his life" by seeking a domestic violence order.

Baxter also accused Clarke of being responsible for him being unable to see his children as much as he used to.

"I'm not going to take it anymore Hannah," he wrote.

"Do you know how hard it is to go to bed every night without your children? I wish you had have just tried.

"I have told the kids that you loved them. They will miss you I'm sure.

"You destroyed my life and I cannot move on. I hope all this was worth it for you and your family."

The letter written by Rowan Baxter was released by the coroners court examining the killing of his ex-wife and children. Photo / Supplied

The letter was released as a court exhibit this week.

A police investigator told the court on Friday Baxter, a former Warriors player, seemed to exhibit "two different personalities" and the letter, which was found on his phone, could be interpreted as a suicide note.

Rowan Baxter killed Hannah Clarke and her three children. Photo / Supplied

"I believe with his personality, his inability to look outward, he needed to maintain this appearance that it wasn't his fault," Detective Sergeant Derek Harris said.

Deputy state coroner Jane Bentley also made public a video filmed by a different police officer's body-worn camera during a traffic stop in September 2019, months before the murders.

In the footage, Baxter can be heard berating Clarke for forgetting to renew a car registration.

The inquest into the deaths of Clarke, Baxter and their children began this week and has heard from former friends and colleagues shedding light on the killer's "controlling and paranoid" behaviours prior to the horrific slayings.

Clarke and her children Aaliyah, 6, Laianah, 4, and Trey, 3 were on their way to school on February 19, 2020 when they were doused in petrol and set a light by Baxter, who killed himself afterwards.

The inquest continues.