Confusion over Vic killer dad's 'threats'

A horror movie temporarily spooked Luke Batty into believing his dad had threatened him with a knife and spoken of "going to another world together", an inquest has heard.

Notes taken by a child protection worker detail an incident in which Luke said Greg Anderson showed him a knife, saying "this could end it all" and "there is a better place for us".

Anderson also talked about the pair "going to another world together", according to the social worker's notes read to the inquest into Luke's death.

But Luke later told a detective he loved his father and that Anderson had not threatened him.

Anderson murdered his 11-year-old son with a cricket bat and knife as they played together in the nets after cricket training at the Tyabb oval in February.

Detective Senior Constable Deborah Charteris told the Victorian Coroners Court she interviewed Luke after his mother, Rosie Batty, raised concerns about Anderson's knife incident with child protection.

But she said Luke claimed he had mistakenly convinced himself that Anderson had threatened him after watching the horror movie A Nightmare on Elm Street.

Det Sen Const Charteris said she interviewed Luke in the presence of Ms Batty, and at one point she interjected, saying Luke had originally been insistent that Anderson had threatened him.

But Luke disagreed with his mother and was adamant Anderson never made a threat, Det Sen Const Charteris said.

Det Sen Const Charteris told the inquest Ms Batty had also said she did not believe Anderson was capable of harming Luke.

She subsequently concluded Luke was not at risk and closed the case shortly after the interview in September 2013.

Her supervising officer, Detective Sergeant Peter Drake, said he came to the same conclusion on Luke's safety.

He told the inquest that had Ms Batty had grave concerns that Luke was at serious risk from Anderson she would have insisted Det Sen Const Charteris investigate further.

"I believe that if it's that strong of a thought then it would've been brought up," he said.