A teacher who sexually abused and murdered the 13-month-old baby boy he adopted with his partner has been told he will spend the rest of his life in prison.

Preston Davey died in July 2023 at the hands of Jamie Varley, 37, who subjected the child to physical, sexual and emotional abuse during the final four months of his life.

Varley, from Blackpool, told police Preston had accidentally drowned in a bath, but a post-mortem examination discovered the child had suffered 40 injuries.

His partner, John McGowan-Fazakerley, 32, who was found guilty of sexual assault, child cruelty and allowing the death of a child, was sentenced to 25 years.

A whole life order means that Varley will never be released from prison, except in exceptional compassionate circumstances.

• Warning: This article contains distressing information

Passing sentence, Mr Justice Turner said Preston had faced "unremitting abuse" and neglect before being killed by Varley during a sex attack.

Turning to Varley, he said: "It was you who did this. You murdered him.

"A whole life order is a sentence of last resort for cases of the most extreme gravity.

"This is a case of the most extreme gravity. You must stay in prison for the rest of your life. You will never be eligible for parole."

Preston's biological mother and grandmother, Sarah and Debbie Davey, were sitting in the public gallery and sobbed throughout the hearing.

In a victim impact statement read out on behalf of Sarah Davey, she said she now lived with the "unimaginable pain of wondering" what her son went through in the final months of his life.

"Those thoughts do not leave me," she said.

"They are with me when I wake up, and they haunt me when I try to sleep.

"The reality of how he suffered is something I will carry for the rest of my life.

"I will never forgive you for what you did to my son and what you stopped him from becoming and achieving in his life."

In a statement read out on behalf of Gary Nolan, the baby's biological father, he said: "Preston was the son that I never got to meet and now never will.

"Upon hearing the news, I remember officers taking hold of me and me blanking out, the next thing I recall is waking up in hospital two days later.

"I am told that I was hysterical and crying and that it was for my own safety that I was taken to the hospital, clearly, I must have been in a bad place mentally."

• As it happened: The sentencing of Varley and McGowan-Fazakerley

Sandra Cooper, Preston's foster mum, told the court he was "joyful, so content and happy, with sparkly smiling eyes".

"That is how we want to remember him," she said.

Her husband Paul told the court: "Saying goodbye to [Preston] and handing him over to Varley and McGowan-Fazakerley was extremely difficult.

"However, we believed at the time that this was the best thing for Preston and he was going to a loving family.

"What happened after this I still cannot bear to think about."

Preston, who was born in June 2022, was taken into care at five days old following an emergency care order by Oldham Council.

He was placed with foster parents, remaining with them for the first nine months of his life.

Preston's mother had been jailed at the age of 14 for the murder of a frail pensioner in 1998 and had been in and out of prison since then.

Varley and McGowan-Fazakerley were approved for adoption in January 2023 and Preston began living at their home in Blackpool in April, when he was nine months old.

But during the four months he was in their care, he was routinely ill-treated, sexually abused and physically assaulted, suffering 40 traumatic injuries.

After Preston began living at the couple's home, he began to suffer non-accidental "cluster" injuries of bruising, seizures or respiratory failures, and there was evidence of abnormality of his anatomy.

In the months before his death, Preston was taken to hospital three times.

Firstly for a nose bleed and seizure, for the second time with a rash and bruising, and on the third occasion with a fractured left elbow.

On 27 July, he was rushed to Blackpool Victoria Hospital by Varley for the final time.

Varley told medical staff he had left the child in the bath for two or three minutes and returned to find him submerged.

But he was dry and there was no evidence Preston had swallowed water.

Medics were unable to revive Preston, and he was pronounced dead in hospital.

A post-mortem examination found 40 external and internal trauma injuries to the child's body, with some consistent with "forcible penetration" and sexual abuse.

It also ruled out drowning as a cause of death.

Ninety minutes before Preston is rushed to hospital, Varley recorded a video, in between using Snapchat and checking emails, of the child in extreme distress, hardly breathing and taking "agonal breaths".

Some of the evidence was too much for one juror, leading to the trial being aborted and re-started with a new jury.

A child safeguarding practice review, paused during the criminal proceedings, will be relaunched by Oldham Council.

Minister for Children, Families and Wellbeing, Josh MaCalister, said he had instructed experts to examine the Preston Davey case.

"It's a really shocking case, people will look at it and feel sick," he said.

"The independent safeguarding review that's now being done will establish more of the facts.

"But I have asked some independent experts to go and look at Oldham, the hospital trust and the adoption agency to see whether things we already know have been acted upon."

After the verdict a spokesperson for Oldham Council said: "The death of any child is a tragedy, but this is a particularly heart-wrenching and disturbing case.

"We are thankful that the perpetrators of the sickening murder and abuse of an innocent child have today been convicted for their crimes."

They said an independent Child Safeguarding Practice Review was already under way, which would examine the handling of Preston's safeguarding.

"Our thoughts remain with Preston's family, loved ones, and the many people affected by this case."

Regional adoption agency, Adoption Now, said it was a "deeply upsetting case, and our thoughts are with everyone affected by these truly awful crimes".

It said it followed "a strict and rigorous process... in the assessment and approval of adopters".

"An independent Child Safeguarding Practice Review is being completed."

• If you have been affected by any of the issues in this story, help and support is available at BBC Action Line.