Luke Batty originally believed his father had threatened him with a knife and spoke of “going to another world together”, but later changed his story when interviewed by police, an inquest has heard.

Luke said Greg Anderson held up the knife as the pair sat in the car together and said “this could end it all” and mentioned “going to another world together”, according to notes taken by a child protection worker.

• Officer makes tearful apology to Rosie Batty

Detective Senior Constable Deborah Charteris told the inquest into Luke’s death she interviewed Luke after his mother, Rosie Batty, raised concerns about Anderson’s knife incident with the child protection worker.

But Luke told Det Sen Const Charteris he loved his father and that Anderson had not threatened him, prompting her to conclude he was not at risk.

He said he had spooked himself into thinking Anderson had threatened him after watching a horror movie, Det Sen Const Charteris said on Wednesday.

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.