It is 10 years since Shannon Matthews was reported missing by her seemingly distraught mother. For 24 days, Karen Matthews played the tearful victim, pleading for the return of her "beautiful princess daughter". When the nine-year-old was found safe, the woman at the heart of the hunt was exposed as a liar. But has the truth behind the kidnapping hoax been fully revealed?
"The first day Shannon was reported missing, I saw it in her eyes. She had this look did Karen, where she wanted to tell you something, but what came out of her mouth was different."
By her own admission, Natalie Murray was responsible for sending her former best friend, Karen Matthews, to prison.
It was three weeks after Shannon was found - drugged in the base of a divan bed at a flat belonging to her mother's boyfriend's uncle - that Natalie's questioning forced a confession.
She had thought from almost the moment the schoolgirl disappeared on 19 February 2008, that something did not add up.
"Straight away my gut was telling me something wasn't right. Karen was carrying on with normal stuff, tidying up the house. It was as if Shannon had just gone to her friend's."
Natalie, a mum of six, lived two doors away from Matthews and her partner Craig Meehan on Dewsbury's Moorside estate.
The pair had been close for years and Natalie knew better than any the chaotic life of her friend - a product of a turbulent childhood who was bringing up four of her seven children, while three lived elsewhere.
"Karen was out on her own from being 15 or 16 and didn't see much of her parents," said Natalie. "She never really got told how to socialise, how to deal with certain situations.
"Any attention, she lapped it up. She couldn't see when people were using her and taking advantage. She got talked into a lot of things by people who she thought were her friends."
But these social inadequacies did little to account for the odd behaviour of a woman whose daughter was apparently missing, thought Natalie.
The day after the schoolgirl was reported missing, the hunt intensified, eventually becoming West Yorkshire Police's biggest operation since the hunt for the Yorkshire Ripper.
Journalists were reporting the story of a stricken community fearing the worst. But inside the house, Natalie noticed a strange chord had been struck.
"It was like a normal day at Karen's," she recalled. "Her and Craig were laughing and joking, playing computer games, like I'd just popped in for a brew.
"I was dying to get her on her own but it was impossible. Craig never left her side and if it wasn't him, there were always others around. They'd be having conversations and if I walked in they'd all go quiet."
Later that night, on 20 February 2008 - despite being told not to by the police - Matthews spoke to the press in a televised appeal.
"She was told in no uncertain terms to let the police deal with the press side of things, that doing anything without their agreement could put Shannon's life at risk," said Natalie.
"Then 10 minutes later I'm standing in the kitchen making the kids' tea and Karen is on the telly doing a live interview.
"I went storming round and said, 'What the hell were you thinking?' And she just said 'Please Natalie, don't shout at me'."
Venting her frustrations at home, Natalie proclaimed "something isn't right", but was dismissed by her then-husband who said she was crazy and that people dealt with grief differently.
In reality, she was piecing together a list of increasingly bizarre behaviour - Matthews's plea for the return of her "beautiful princess daughter"; how she clutched a teddy during an appeal that did not even belong to Shannon.
"She'd never called Shannon a princess. Someone must have told her to say that," said Natalie.
"The teddy wasn't Shannon's.. She came down the stairs with it before the press conference and I asked if it was Shannon's.
"She said 'I don't know'."
Meanwhile, the residents of Moorside had pulled together and printed their own T-shirts and posters, while more than 300 police officers and three-quarters of all the UK's specially trained "body dogs" scoured the area.
"I don't think people understood the significance of what we were dealing with," said Barry South, divisional commander of policing in Dewsbury at the time.
"It was a schoolgirl who had gone missing, we've had it before and they're usually home by bed time. But it quickly became clear this was totally different."
The officer first encountered Matthews before a media appeal.
Recalling her nonchalance in the absence of reporters, he said: "I remember thinking whether she was autistic because she was laughing and smiling.
"Immediately I thought, 'Something's not right with this woman'."
Then on 14 March, detectives received a tip-off from a member of the public to search a flat a mile away from the estate, belonging to Michael Donovan, the uncle of Craig Meehan.
There, hidden in the base of bed, Shannon was found - drugged, frightened and crying, but alive.
By the time the schoolgirl was found, Natalie's suspicions - coupled with claims those involved had planned to share the £50,000 reward money - had soured her relationship with Matthews and left her feeling betrayed.
"I'd given her so many chances to talk. I'd told her, 'Look Karen, if there's anything you want to tell me, you can. We can try and sort it.' "
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Matthews was moved off the estate not long after Shannon was found.
Her daughter was taken into care and allowed only supervised visits with her mum, who had now become close to another Moorside resident, Julie Bushby.
But for Natalie, the niggling doubts continued.
She knew Matthews and Meehan's relationship had hit a rough patch and she had heard rumours Matthews had planned to leave her partner for Donovan - allegedly arranging for Shannon to stay at his house until Meehan had moved out.
"We were trying to wrap our heads around it all, who we could and couldn't trust. In the end I said we need to see her and tell her straight," recalled Natalie.
Together with Julie, whose initial belief in Matthews was starting to falter, a meeting was arranged to confront her with Det Con Freeman, the family's police liaison officer.
She too had voiced concerns about the mum-of-seven's seemingly unflinching reaction to the news her daughter had been found.
The women gathered in the officer's car; Matthews in the front, refusing to acknowledge or meet the eye of her key interrogator, who was by that point fired up to get to the bottom of her friend's deceit.
"I said 'Look Karen I'm not going to beat about the bush. There's a lot of stuff I've seen you do and say, none of it adds up to me. You know I know there's something going on'," said Natalie.
Matthews took "a massive sigh, dropped her shoulders" and admitting her lie, said "yeah it's true".
Two days later, on 8 April, Matthews was charged with perverting the course of justice and child neglect. Donovan had already appeared in court charged with kidnap and false imprisonment.
Contradictory explanations were given by the pair. In court, Matthews blamed Donovan and her former partner and his relatives, painting a picture of herself as the "fall guy".
They were later each jailed for eight years.
Shannon, who is now 19, was placed in the care of social services before being given a new identity and family. During her mother's trial, a court was told in the aftermath of being found, she regularly had nightmares and needed psychotherapy sessions.
Matthews, meanwhile, was released in 2012, given a new name and is now reportedly living in the south of England.
Legally the case may be over. Det Ch Supt Mark Ridley, of West Yorkshire Police, said: "To this day, there is nothing to suggest there is any reason to re-open the case."
But Natalie, who has since moved off the estate, is sceptical the pair acted alone, citing Matthews's vulnerability at being easily influenced and claims that a neighbour of Donovan's regularly saw a couple visit his flat during the time Shannon was missing.
Not alone in her doubts, Det Con Freeman, with 30 years policing experience, questions whether others had a hand in the plot.
"I'm not sure. I have my theories."
But, she said, without Natalie the truth may never have unravelled.
"She is the best detective that didn't join the police that I've ever met. She knew Karen before this and how she'd behave, so she was key to us solving the case."