A stepmother accused of killing a five-year-old girl by forcing her into a bath of scalding water left her with burns so severe her heart and lungs failed, a trial has heard.

Janice Nix, now 67, allegedly meted out cruel punishments to Andrea Bernard and her then eight-year-old brother Desmond Bernard that went 'beyond chastisement even by contemporary standards'.

Nix was 19 when she is said to have forced Andrea to take a bath at their home in Thornton Heath, south London, on June 6, 1978 - with the young girl dying in a specialist burns unit five weeks later.

The death was not treated as suspicious at the time and police only began investigating in 2022 after Desmond Bernard went to the police on October 6 that year.

He was encouraged by his birth mother who said Nix was planning to release a book about her life.

Nix, of Rodenhurst Road, Clapham, denies the manslaughter of Andrea and child cruelty to Desmond.

Isleworth Crown Court heard from forensic pathologist Dr Stewart Hamilton, who took the stand as an expert witness commenting on the coroner's report in 1978.

The report gave cause of death as 'cardio respiratory failure' caused by sepsis due to 'complications from severe burns'.

The court was told Andrea suffered '50 per cent full-thickness dermal burns' in areas of her chest and lower abdomen, lower two-thirds of her back, and the perineal region of her inner thighs.

Dr Hamilton said: 'Burns are a remarkably complex form of injury, especially if the skin is removed and the wound is essentially exposed.'

He added the burns have other 'significant adverse effects', including loss of fluids and disruption of the 'balance of salt levels', which 'dampens down the immune system.'

'Overall, these burns, these scalds, have produced a risk of infection that has spread through the body.

'Ultimately, that was too much for the body to cope with, and the heart and lungs failed.'

He went on to say the distribution of scalding 'would have been consistent with Andrea sitting in the bath water,' adding observations from the coroner's report show the five-year-old was otherwise healthy at the time.

Earlier jurors heard contemporary police statements in which Nix described Andrea as a 'happy and co-operative child' who was 'obedient' and 'very independent'.

She told police she was in the garden when the children came home from school and said: 'Go and have a bath, Desmond first, and Andrea.'

'But 15 to 20 minutes later Andrea came out and said: "Mummy, my legs are itching".

'I saw her legs were bright pink and peeling. I picked her up, and she fainted.'

But in a later statement she said Andrea was by the garden door and 'scratching' the wound before the skin fell off.

She said she 'panicked' and asked a neighbour to take her and Andrea to the hospital.

In 1978, a coroner had ruled Andrea's death after Nix told police of the 'terrible, tragic' circumstances.

But the investigation was reopened after Andrea's older brother Desmond went to police in 2022, stating that keeping quiet about what he said happened had 'become a burden he could no longer carry'.

He said Nix regularly beat the siblings, and told him she would 'never hit him again' if he said his sister fell into the bath at their home in Thornton Heath, south London.

Isleworth Crown Court heard both children were on the receiving end of 'sustained beatings' in the run up to his sister's death after they were rude to her.

Earlier this week, prosecutor Kerry Broome told jurors: 'This, say the Crown Prosecution Service, was the start of a cycle of violence which left the children terrified and in extreme fear and terror of Janice.

'If the children did something Janice perceived as wrong, she would wait until their father was not around then would punish them.'

Desmond recalled a different version of events to police, stating that Nix had been inside at the time when he heard his sister screaming.

The prosecutor said Desmond remembered his stepmother was 'fuming' the day of the bath scalding.

Ms Broome said: 'Janice called for Andrea to get in the bath.

'Just afterwards, Desmond could not see what was happening in the bathroom, but he heard Andrea screaming, and saying: "It's hot, it's hot".

'Janice kept shouting at her to get in.

'He says: "Andrea would not stop screaming and I can't remember how long it went on for, but then it just stopped".

'The next thing Desmond heard was Janice telling Andrea to wake up. She sounded like she was panicking.

'When Desmond went into the bathroom, he found Janice holding Andrea in a towel.

'Andrea was not awake - she was limp and Janice was cradling her. Skin was coming off from her legs.

'To Desmond, Janice seemed scared and asked him to say it was an accident and that Andrea fell into the bath.

'She promised never to hit him again if he said that, so that is what he did - he told everyone it was an accident, and Janice never hit him again.'

The court heard Nix moved into the Bernard family home with the children and their father, Desmond senior.

He had already split up with his wife, Angela, who had recently served a short jail sentence.

Jurors were told Nix then began beating the children, at least once or twice a week, often while Desmond senior was working away as a chauffeur.

Desmond junior told police in 2022 this included being hit with a pot, being bitten by Nix, and being forced to eat cat food.

Ms Broome said: 'The prosecution say these were serious, violent, cruel, degrading and unacceptable forms of punishment, even by the standards of the late 1970s.'

The beatings were so severe that Nix's own mother told her to stop, while her brother said Nix was 'horrible to the children', the court heard.

The prosecutor said: 'For the best part of half a century, her death - and her immersion in the scalding bath which led to it - was treated as an accident.

'But in September 2022, Desmond, now a fully grown adult, contacted the police and provided an account which explained the defendant's treatment of him and his sister Andrea was not how it seemed at the time.

'That led to the events of the late 1970s involving the Bernard family being investigated by the police.'

The court heard a one-day inquest was held into Andrea's death, just a week after she succumbed to her injuries.

In it, it gave the cause of death as cardiac arrest, septicaemia, and burns. It is believed Andrea was placed in water at least 45C but potentially much hotter.

The coroner recorded a conclusion of accidental death, and was not investigated by police until four years ago when Desmond contacted them.

Ms Broome said new and historical evidence suggested Nix was present in the bathroom and ran the bath for Andrea, and that Nix instructed the little girl to get in.

She said: 'It was a punishment, it was intended to cause pain at least.'

Nix, of Clapham in south London, denies manslaughter, and one count of child cruelty relating to Desmond between 1975 and 1978.

Nix denied being present when Andrea got into the bath, and suggested Desmond's allegations were linked to a financial dispute.

The trial continues.