Shannon Matthews disappearance: New doco reveals how mum kidnapped her own daughter

When English schoolgirl Shannon Matthews turned up alive 24 days after she went missing in 2008, you'd expect her mother to be overcome with emotion and relief.

But Karen Matthews' web of lies and her sinister plot was about to be uncovered - because she had just kidnapped her very own 9-year-old daughter.

With the help of her partner's uncle Michael Donovan, the pair cooked up an evil plan to make cash from the reward money for Shannon's disappearance.

Less than a year after Madeleine McCann had disappeared, the pair started dreaming up their twisted plot.

A whopping £3.2 million ($6.13m) was used in a manhunt to find Shannon, including reward money.

After 24 days, police found Shannon drugged and hidden in the base of a bed at Donovan's flat in Yorkshire.

Shannon's discovery also uncovered her mother's sinister plot, which has been the topic of a new British documentary, The Disappearance of Shannon Matthews, which details how the desperate search for the missing child unfolded.

In it, the disturbing truth of how Shannon was horrifically exploited by her own mum was uncovered - and how she shamelessly played on public sympathy by posing as a worried parent.

Karen Matthews posing with Shannon's favourite teddy bear in an emotional appeal for her safe return in 2008 - but it was all a lie. Photo / Getty

THE PLOT

It was February 19, 2008, when Karen tearfully told the emergency operator Shannon hadn't come back home from school, which was around 800 metres from their home in Yorkshire.

More than 3000 homes were searched and 10 per cent of the local police force was assigned to the case.

Big cash rewards were offered for any information that could lead to Shannon's return.

A British newspaper offered $40,000, but upped it to $100,000 after the youngster had been gone for 20 days.

Her mum Karen was the most outspoken during the manhunt, leveraging sympathy at every turn and appearing to live through every parent's worst nightmare.

In one interview she spoke about how she couldn't go into Shannon's room, and said her 2-year-old sister Courtney would cry for her 'missing' older sibling.

"You hear her shouting for Shannon," Karen told the Yorkshire Evening Post.

"It is heartbreaking. She doesn't understand as much as the other kids but she is starting to realise Shannon has been gone a long time."

But all along, Karen had her eyes on the reward money.

The search for missing Shannon made headlines around the world. Photo / Getty

'NOBODY THOUGHT WE'D SEE HER ALIVE AGAIN'

Karen eventually planned to "find" Shannon - but her plan backfired when police found her first.

On the 24th day she was missing, two detectives broke down in tears after they emerged with the schoolgirl after believing she was dead.

She was found under Donovan's bed at his flat, just a mile from her own home.

Donovan was also hiding under the bed when cops stormed his flat.

Detective Constable Paul Kettlewell told The Mirror: "I was elated. I couldn't believe we'd found her and she was alive.

"As we went down the stairs it was like carrying my own child.

Detective Nick Townsend, who was with Paul when Shannon was found, added: "Nobody ever thought we'd see Shannon Matthews alive again, so to see her in the arms of PK …

"It's hard to describe the emotion. You just want to cheer. I can't describe anything other than euphoric."

Donovan was arrested at the scene.

Supporters and family members walked through the neighbourhood in search of Shannon. Photo / Getty

PLOT TWIST

Despite Donovan being arrested, police made a disturbing find - Karen's partner Craig Meehan, was found to have child sex abuse images on his computer during the police search for Shannon.

While he was later convicted for his crimes, he had nothing to do with Shannon's disappearance.

While Donovan was arrested, police interest soon fell on Karen.

When police told her Shannon was still alive, Karen didn't even ask how she was – it was like she already knew.

Michael Donovan was also charged and found guilty of Shannon's kidnapping. Photo / Getty

DRUGGED AND RESTRAINED WITH NOOSE

Karen was arrested and charged with child neglect, kidnapping, perverting the course of justice, and false imprisonment.

At trial, one hideous revelation after another about what she and Donovan subjected Shannon to came out.

The little girl had been drugged with temazepam – a powerful sleeping pill – along with travel sickness tablets.

She had also been restrained with a strap tied to a roof beam that had a noose on the end.

Whenever Donovan went out, Shannon was tied up.

During her captivity, Shannon was made to follow a list of rules, including "you must not make any noise or bang your feet" and "you must not go near the windows".

They were eventually going to let Shannon out and "discover" her, claiming the $100,000 cash reward for themselves.

In December 2008, the jury found Karen and Donovan guilty and both were sentenced to eight years in prison.

Karen was released in 2012 after serving half her sentence after Donovan had already been released at an earlier date.

Shannon was given a new identity and was sent to live with a new family.