A mother and her boyfriend have been jailed after her five-month-old baby was violently abused and died.

Katherine Cox, 33, did nothing as partner Danny Shepherd, 25, lost his temper with baby Eli Cox, shaking him violently and banging his head.

The infant later died in hospital having suffered a "catastrophic" brain injury.

Medical staff found he had sustained some 28 bone fractures, believed to have been inflicted over a 10-week period, with a pathologist concluding the infant had been "twisted, pulled, crushed and bent in half".

Furthermore, traces of cocaine and amphetamine were discovered in baby Eli's system.

Shepherd was jailed for 13-and-a-half years and Cox for eight after being found guilty of causing or allowing the baby's death.

Passing sentence at Maidstone Crown Court on Tuesday (14 November), Mr Justice Stuart-Smith said he accepted Cox had not inflicted any of the injuries or been present at the time.

But he told her she knew the "risk" Shepherd posed and "put her life with him before the safety of her child".

"I am sure that it was you Danny Shepherd who inflicted the injuries that killed Eli," he said, as reported by the Daily Mail.

"You continue to deny it but you know it's true. I am also sure it was you who inflicted the earlier injuries. In normal speech, you lost it as you had lost it before, but you lost it majorly and inflicted serious violence upon Eli causing his death.

"All of this could have been avoided had you just stayed away from him, having lost it on previous occasions."

He added: "For much of his life Eli would have been in pain from the fractures you inflicted. He was particularly vulnerable as he could do nothing to protect himself or draw attention to his suffering.

"You knew what you had done in the past and you knew you were in danger of doing it again.

"In your case Katherine Cox I am sure that you didn't inflict the injuries and I am not sure you took part in or were present when he inflicted the earlier injuries.

"But I am sure that you knew that Danny Shepherd caused significant injuries to Eli and that there was a risk he would do it again. It is one of the shocking features of this case that you put your infatuation with Danny Shepherd before the safety of your baby.

"You bear a heavy responsibility for what happened to Eli. You have lost everything."

Cox and Shepherd, of Lapwing Close, Minster-on-Sea, on the Isle of Sheppey, were also found guilty of possessing a class B drug.

Their trial heard how an ambulance was called to their home at around 5.30pm on 13 April 2016 when Eli stopped breathing.

He was taken to Medway Maritime Hospital but died on 27 April.

A paediatrician had noticed a number of bruises that were not believed to have been accidental and Kent Police launched an investigation.

Medical evidence later showed Eli's brain injury must have happened immediately before his collapse.

They also found that the bone fractures would have been suffered during at least five separate incidents beginning in late February 2016, and that it would have been obvious to the offenders Eli was in pain.

Both Cox and Shepherd denied being users of cocaine and amphetamine, despite five wraps of the latter substance being found by police in a garden shed at their home.

Senior investigating officer Detective Chief Inspector Ivan Beasley said: "The death of a child is never anything less than tragic but the circumstances behind Eli Cox's passing are especially upsetting for those of us who share a compassion for others.

"None of us will ever understand what compels people to cause harm to children, and it is unfortunately true to say that Eli suffered more than most and was robbed of his life before it had barely begun.

"Katherine Cox and Danny Shepherd maintained their innocence throughout but the jury saw through their lies. Only they know the true extent of the abuse Eli was put through, which is simply unthinkable to most members of society, including parents who would do anything to protect their children from harm."

A serious case review is under way to establish if Eli's death could have been prevented by the authorities.