A man who murdered the teenage girl who called him her father, after she claimed he had sexually abused her “over a number of years”, has been sentenced to life in prison and must serve 32 years before he can be considered for release.

Scott Walker, 51, has not told police the location of 17-year-old Bernadette Walker’s body, which has not been found despite searches, and it is not known how she was killed.

Judge Mrs Justice McGowan, sentencing at Cambridge Crown Court, said Scott Walker’s refusal to tell police where Bernadette’s body is “means she can’t be shown the respect she deserves”.

“Cruellest of all it’s likely to mean some members of her family and friends will go on hoping she might be alive and might someday come back into their lives,” she said.

Photography student Bernadette was last seen alive on July 18 last year when Scott Walker, who was not her biological father, collected her from his parents’ house in Peterborough.

Prosecutors said that Scott Walker killed Bernadette to “prevent her pursuing her allegations of sexual abuse any further”.

She had written in a diary entry: “Told my mum about my dad and the abuse.

“She called me a liar and threatened to kill me if I told the police.”

Scott Walker said that Bernadette ran away from his car when he stopped the vehicle, but jurors at Cambridge Crown Court rejected his account, convicting him at an earlier trial of murder.

Lisa Wilding QC, prosecuting, said that Scott Walker formed an “unholy alliance” with Bernadette’s mother, his ex-partner Sarah Walker, to cover up the girl’s death, sending messages from Bernadette’s phone to give the impression she was still alive.

Sarah Walker, 38, was convicted of perverting the course of justice and sentenced to six years in prison.

The judge said she was “sure Sarah Walker was the guiding mind behind the detail of (the) plan” to cover up Bernadette’s death, adding: “Each defendant was a willing party in that enterprise.”

The prosecution said Bernadette had told her mother on July 16 that Scott Walker had sexually abused her “over a number of years”, but that Sarah Walker did not believe her daughter’s allegations.

Scott Walker told jurors that Bernadette’s allegations of sexual abuse were “untrue”.

The prosecution said that Bernadette was sent to stay with Scott Walker’s parents overnight on July 17 “while things calmed down a little”, with Scott Walker collecting her on July 18, when she was last seen alive.

Ms Wilding said that Scott Walker’s phone, “which was usually in regular use”, was off between 11.23am and 12.54pm on July 18.

“The prosecution say that in that hour-and-a-half he killed Bea,” she said.

Ms Wilding said that when Scott Walker’s phone reconnected to the network at 12.54pm, the first call he made was to Sarah Walker, which lasted for more than nine minutes.

The prosecution suggested the pair “concocted” a story during this call to cover up Bernadette’s disappearance and death.

Sarah Walker reported Bernadette as missing to police in the early hours of July 21.

Sarah Walker was not married to Scott Walker but had changed her surname to Walker by deed poll.

At the time of Bernadette’s disappearance, Scott and Sarah Walker were living at the same address but Sarah Walker was in a relationship with another man.

Sarah Walker was found guilty of two counts of perverting the course of justice “knowing or believing” Bernadette to be dead, having already admitted two counts of perverting the course of justice.

These were by sending messages from Bernadette’s phone after she disappeared and by providing false information to the police relating to her disappearance.

Scott Walker was found guilty of murder and of two counts of perverting the course of justice.

They were sentenced at Cambridge Crown Court on Friday and remained silent as they were led to the cells.