A teen has recalled the moment his father "in a rage" allegedly repeatedly slashed his mother with an axe and then turned the weapon on him when he tried to run for help.
Dinush Kurera's 19-year-old son gave evidence to a Supreme Court jury on Thursday about the evening his father killed his mum in their family home.
The 47-year-old man admits killing his estranged wife Nelomie Perera, in December 2022, but has pleaded not guilty to murder as he claimed to have acted in self-defence to save his own life.
Kurera also denies several elements of the killing and claims he did not assault his son, whom AAP has chosen not to name.
The son, who was aged 17 when his mother died, gave evidence to 14 jurors video link from a remote location on Thursday.
Kurera sat emotionless in the back of court as he watched his son detail his alleged violent assault on Ms Perera.
After 11pm on December 3, the teen said he heard screaming coming from downstairs.
He and his younger sister went downstairs and saw Kurera standing near the back door with an axe "raised above his shoulder".
"I couldn't see mum, the dining table was obstructing my view of her, however I could hear her in pain," he said.
"I assumed that mum went to go have a smoke and that Dinush would be hiding in the backyard, because mum was very paranoid about keeping the doors unlocked and she wold never leave it open."
The teen alleged his father threatened to kill them all, by pouring gasoline around the house and setting it on fire, if they tried to run away.
Ms Perera begged for an ambulance, but Kurera instead asked his son to get an ice pack for her, he said.
The teen said Kurera allowed his mum to go to the toilet and the family moved to the couches in their lounge room.
He said when Kurera asked if his mother was seeing other people, the teen replied "she had been seeing several people".
"She said 'you called me a ho so I decided to be one', that's when Dinush got up and swung the axe, but stopped short of hitting her," the teen said.
"She brought up the cheating situation ... Once she said that though Dinush got up, in a rage, and had this aggressiveness I've never seen from him before."
Kurera swung the axe into Ms Perera three times "in the span of five seconds" while she sat in the recliner, he said.
"She looked lifeless each time he swung, and she just took it," the teen said.
"I saw blood coming out, so when he went to go for the fourth swing I ran towards the rear sliding door."
But the door was stuck and he said Kurera caught up with him, hitting him in the head with the axe.
He got the door open and alleged Kurera hit him with the axe on his shoulder, causing the teen to fall onto the ground.
"I grabbed one of the outside door chairs and used it as a shield, however he swung the axe at my left knee and it connected with the sharp end," he said.
"Someone had dragged Dinush off of me, which gave me time to run down the side of the house onto the street ... and scream for help."
Kurera denies he hit Ms Perera with an axe in the lounge room, and that he assaulted his son with the weapon, his lawyers previously said.
The trial before Justice Amanda Fox continues.
