A woman accused of murdering her six-year-old stepson is said to have told her cellmate “the little f**ker tried to get out the front door and I stopped him trying to follow his dad”, a jury has heard.

Emma Tustin, who is accused of fatally shaking and hitting Arthur Labinjo-Hughes, leaving him with an “unsurvivable” brain injury, made the remarks during a heated row with the prisoner while awaiting trial.

Prosecutors have alleged the killing blows were inflicted by Tustin on Arthur – who by this time had been weakened by months of “cruel” abuse, salt poisoning and starvation – while in the hallway of her home, next to the front door.

Tustin, 32, denies murdering Arthur, who jurors previously heard looked “broken” just a few weeks after he moved into Tustin’s home with his father, Thomas Hughes, at the start of the March 2020 lockdown.

Tustin and Hughes are accused of murder, of poisoning Arthur by forcing him to eat salt-laced meals and of inflicting months of “cruel” abuse, likened to “torture” by prosecutors.

The youngster died in hospital on June 17, 2020 after he was shaken and his head “banged repeatedly against a hard surface”.

It is alleged “coercive” 32-year-old Tustin carried out the fatal assault at her home, before photographing her stepson as he lay dying in the hallway, using her mobile phone.

Jurors heard the prison row was triggered when a fellow prisoner told Tustin she “didn’t believe” her account of how Arthur came to be mortally injured, while alone with his stepmother at home in Cranmore Road, Solihull, on June 16, 2020.

Bernard Richmond QC, for Hughes, cross-examining Tustin, asked her about the exchange with the female prisoner – which ended up with the pair being moved to separate cells – some months before the trial.

Giving evidence for a third day at Coventry Crown Court on Thursday, Tustin said: “I had told her he (Arthur) had done that on a number of occasions, but not on this occasion.”

She described Arthur “trying to escape” on “three or four previous occasions”.Mr Richmond asked: “So let’s be absolutely clear – it is absolutely not the case that you never uttered the words ‘the little f**ker tried to get out the front door and I stopped him going after his dad’?”

Tustin replied, “No – I did call him a little f**ker”.

Later, she added the words used were correct, “apart from” her saying she had “stopped him” – but that her words were not about the incident of Arthur’s fatal collapse.

Earlier, Tustin also claimed a host of medical experts were wrong to conclude the boy suffered fatal injuries that could not have been self-inflicted.

She previously claimed to have heard a “bang” and a “loud crack”, and suggested the boy may have thrown himself or fallen down the stairs at her home.

When asked about medical evidence that her own legal team have accepted as true, stating that Arthur’s injuries could not have been self-inflicted, Tustin said: “It’s not first time medical experts have been wrong, and it won’t be the last.

“In this case, it’s not murder, murder was not committed.”

She added: “I didn’t shake him, I would never shake a child, just like I would never poison a child, or kill anybody, let alone a child.”

Mr Richmond asked: “So if Arthur didn’t do it to himself… then the only person capable of doing that is you?”

She replied: “That’s not true, because I did not do it.”

Asked to suggest “any other candidate” for having inflicted the fatal injuries, Tustin replied: “I was the only one there, nobody else was there.”

Later, she said: “I didn’t push him (Arthur) down the stairs, I didn’t bang his head, so whatever has happened, it has been done by his own actions.”

Richmond then asked: “You’re trying to control the story aren’t you?

“You know full well what you’ve done?”

Tustin replied: “I haven’t done anything.

“I have admitted to what I’ve done, I’m not willing to admit to something I haven’t done.”

Though not present for the fatal assault, “bullying” Hughes, 29, of Stroud Road, Solihull, is alleged to have aided in the murder, and also faces three counts of child cruelty.

Tustin, who has admitted one count of child cruelty but denies two other similar charges and murder, will continue to be cross-examined on Thursday.