A 20-month-old toddler was happy watching Dora the Explorer before being attacked and later dying, a NSW murder trial has been told.
Timothy Andrew Whiteley, the man accused of murdering the toddler, told police he initially believed the girl had fallen out of bed and hit her head.
Whiteley, 28, who had been in a relationship with the girl's mother, is standing trial in the Newcastle Supreme Court having pleaded not guilty to murdering the toddler.
Weighing 11kg and standing 84cm tall, the toddler died from multiple injuries, including bleeding to the brain, broken ribs, a collapsed lung, lacerations to her liver and bleeding in her abdominal cavity.
The jury has been told she had suffered a number of blows or kicks to the body.
In a videotaped record of interview played to the court on Thursday, Whiteley told police he tried to save the girl's life by giving her CPR after noticing she wasn't breathing.
Whiteley said the toddler had been happy but a little grumpy at times earlier in the day waiting for her breakfast at a house in the Hunter region on June 19, 2018, before watching Dora the Explorer on television.
He went to put her down to sleep - "just routine as normal" - at about noon before hearing a loud thud soon after and finding the toddler lying face down on the floor in her bedroom, appearing to have been knocked out.
Whiteley said he called out to the girl's mother - who has been charged with manslaughter - and they believed she must have hit her head on the chest of drawers during the fall.
"It just sounded like something hit the ground really hard. The thud kind of scared me," Whiteley told police.
But he claimed the girl's condition soon started to improve and she was splashing water around when the couple gave her a bath.
"We thought the worst of it was over," Whiteley said.
He said it was only until a few hours later when he came back inside the house after having a cigarette and spending time with the dog that he realised the toddler wasn't breathing and an ambulance was called.
The toddler's older sister kept asking why she wasn't waking up.
The crown case against Whiteley is he was the only adult in the toddler's bedroom when she was attacked.
Whiteley claims he didn't cause the girl's injuries or take part in the attack.
The toddler's mother has also denied inflicting the injuries.
An ambulance was not called until 4.59pm despite the toddler appearing to be in a clearly distressed state, unconscious and not responding, the court has heard. She was pronounced dead at 6.03pm at John Hunter Hospital.
The trial before Justice Stephen Rothman continues.