A stalker who lay in wait for his ex-girlfriend before he kidnapped her, violently drowned her and then had sex with her as she was dead or dying has been jailed for a minimum of almost 24 years.

Andrew Pearson, 45, conducted a dry run and took photos of the various scenes days before he ambushed Natalie Harker and forced her into woodland near Colburn, North Yorkshire, where he had hidden a tent.

Police found her bruised and naked body under a sleeping bag around 12 hours after Pearson had grabbed her when she was cycling along a secluded path to work in the dark on October 9 last year.

Judge Stephen Ashurst, sentencing at Teesside Crown Court, said only Pearson would know precisely what happened when he killed her by holding her underwater while compressing her neck.

The judge said: “What happened thereafter was extraordinary.

“You took her lifeless body into the tent, stripped her of her clothes which you then folded and took into another part of the tent.

“Whether she was still breathing or not, you thought only of yourself, not just in the shock of the moment, but for hour after hour.”

At some point Pearson had intercourse while Ms Harker was unconscious or dying, the court heard.

He did not summon help for the 30-year-old churchgoer, but messaged a friend in the US, saying: “Goodbye, I have killed Natalie, I’m going to hand myself in.”

He then spent 42 minutes on a FaceTime call with that friend while in the tent with his ex-girlfriend’s body.

Pearson did not confess to police.

Instead during a 999 call around 12 hours after he had abducted her, he tearfully claimed she had fallen into a stream and that he had dragged her out and then collapsed after trying to perform first aid.

The couple had split weeks before and Ms Harker, a popular and conscientious medical centre cleaner, had told family and friends she was scared of her ex who was pestering her by text.

Two days before she was killed she told people at her church she was worried she was being followed.

The judge said sadly she did not take advice to contact the police, saying: “I tend to take the view that’s likely to be because Natalie thought the best of people.

“She was trusting and naive.”

Chloe Fairley, prosecuting, said Pearson knew his victim’s routine of cycling to work before dark and was aware that she was frightened of that section of cycle path where he lay in wait.

He had taken photos on his phone days before of keys sites and had set up a hidden woodland camp across a field from the abduction site.

The murder was aggravated by the fact she was a vulnerable woman with some learning difficulties and that he had stalked and kidnapped her.

In statements read out at court, her brother Alistair and parents John and Deborah expressed the huge impact her murder had had on their tight-knit family.

Mr Harker, a school bus driver from Colburn, said: “Was she calling out for me, was she in pain?

“These are questions I always ask myself.”

Pearson, of Chestnut Court, Catterick Garrison, denied murder and kidnap but was convicted on Thursday following trial.

John Elvidge QC, defending, said the killing, as opposed to the kidnap, was not premeditated.

The judge imposed a life sentence with a minimum term of almost 24 years taking into account time already served on remand.