The jury at a Hong Kong murder trial on Wednesday heard a child recall hearing her five-year-old stepsister say she was “very scared” before falling unconscious at home and dying later the same day.

In an interview with police played at the High Court, the seven-year-old, who is serving as a witness against her parents, also recounted how her stepfather had “forcefully” thrown her stepsister upwards, hitting her head against the ceiling seven to eight times on the night before she died.

Her mother, she said, was watching and urging him on.

“[They] wanted to scare her,” the child said. “Because caning her with a rattan stick was useless.”

She said her parents then swung her sister horizontally, threatening to let her go, then set her down and made her practise walking in a straight line. The deceased girl and her eight-year-old stepbrother were also forced to eat while standing next to the door holding their bowls in their hands, she said.

“Why couldn’t they eat together [with you]?” the interviewing officer asked.

“Because they lacked table manners,” the girl replied. “I don’t know what that means. Papa, mama and granny said it.”

She added that her sister trembled that night and repeatedly said she was “very scared”.

The next morning, she recalled, her sister felt dizzy and again said she was“very scared”, but did not respond when asked why. She fainted a short time thereafter.

The five-year-old died of septicaemia in hospital hours later at 2.38pm on January 6, 2018.

Prosecutors said her death was a murder indirectly caused by the assault, ill-treatment and neglect at the hands of her 29-year-old father and 30-year-old stepmother, from August 10, 2017.

The couple has denied the murder charge, but have admitted child cruelty towards the deceased and her biological brother during the same period. The children’s 56-year-old grandmother has denied all four counts of child cruelty with which she has been charged.

None of the defendants or their relatives can be named due to a gag order from Mr Justice Albert Wong Sung-hau aimed at protecting the identity of the children.

The deceased was introduced only as Z, while her stepsister and brother were respectively identified as Y and X.

Much of Y’s evidence was introduced to the jury through a police interview she recorded the day after her sister died.

Her testimony revealed that the three siblings used to sing in bed and play in a makeshift tent made of blankets at home.

When asked what her siblings’ lives were usually like, Y told the officer: “Hit by papa, and hit by mama.”

She said her siblings were assaulted on more than 110 occasions, which were at times witnessed by their grandmother, who would not stop them.

“Because she also found them naughty, and she would hit them,” the child said before imitating the whipping sound of the rattan cane.

Y noticed her brother had “many cane marks” sustained as a result of beatings with the rattan stick to his face, hands, legs, buttocks and soles.

She said her parents would also hit them with a pink slipper, while her stepfather would use his fists.

“Sometimes there was a lot of blood,” she continued. “Stuck to the bottom of the slipper.”

“Did you say anything?” the officer asked.

“No,” Y replied. “I was scared that I would be hit if I spoke up.”

She also recalled watching her injured siblings pick the wounds, or even peel away the scabs, adding that their parents would disinfect them with rubbing alcohol when they got serious.

Asked why they would pick those wounds, she replied: “Perhaps they wanted to ruin their own hands. They would even eat faeces.”

She added the pair would not shower, which made her mother and grandmother prepare a sleeping bag for them to sleep in the corner “because they were dirty”.

Under cross-examination in court, 11-year-old Y agreed with her stepfather’s defence counsel, Alex Ng, that it had been fun to be thrown in the air.

Y said she had also been tossed in the air on January 5, though her head never touched the ceiling.

She also agreed with her mother’s counsel, Caesar Lo, that her siblings would often ignore their stepmother’s instructions.

But she disagreed with suggestions from her grandmother’s counsel, Chase Pun, that the grandparent had never hit her stepbrother with the stick.

“I had seen that,” she replied, her voice faltering. “In the course of hitting him, it struck his heel and he said it hurt.”

When a similar question was put to her again moments later, she repeated: “I clearly remember granny used the rattan stick to hit my brother – hit him on the body, hit him on the buttocks.”

The trial continues on Thursday.