Nine-year-old's disappearance gripped the country, but details gradually emerged of a 'truly despicable' kidnapping plot

West Yorkshire police's investigation into Shannon Matthews's disappearance would end up costing more than £3.2m. Photograph: Christopher Furlong/Getty Images

For more than three weeks, the image of a grinning Shannon Matthews had been plastered across newspapers and TV screens, together with the strained face of her tearful mother Karen.

Detectives had abandoned murder investigations to join the team searching for the nine-year-old who did not come home from a school swimming trip. It would be West Yorkshire police's biggest such operation since the hunt for the Yorkshire Ripper, and end up costing more than £3.2m. Sniffer dogs were brought in from around the country and hundreds of local people helped scour the area for any trace of the little girl.

But as time passed, hope of finding Shannon alive began to fade, and when she was found hidden under a bed in a flat a mile and a half down the road, there was delight and amazement – not least from Detective Superintendent Andy Brennan, the experienced murder specialist heading the inquiry.

Yet there was another twist to come. As Michael Donovan was dragged from his property in Batley Carr, he yelled to officers: "Get Karen down here! We'd got a plan. We're sharing the money – £50,000."

What emerged in court as Matthews and Donovan were tried for kidnapping, false imprisonment and perverting the course of justice was what the judge would go on to describe as a "truly despicable" plot.

Matthews, a mother of seven, planned to stage her daughter's disappearance and keep her captive with Donovan, her then partner's uncle, in a bid to claim thousands of pounds in reward money when Shannon was eventually "found".

Police said it was possible they had been influenced by the international coverage of Madeleine McCann's disappearance 10 months earlier, and there were even claims – discounted by detectives – that the plot could have been inspired by a storyline in the TV drama Shameless, where a young boy had been abducted by his sister to try to extract a £500,000 ransom.

After she was recovered, Shannon was discovered to have traces of temazepam and the travel sickness medication melcozine in her system, part of an apparent attempt to keep her subdued and drowsy. In the loft of Donovan's flat, officers found an elasticated strap, thought to have been used to keep Shannon safely tethered when he went out. "Kidnap rules" were designed to stop her making noise that might reveal her presence to neighbours.

Convicted on all counts at Leeds crown court in December 2008 after a three-week trial, Matthews and Donovan were each jailed for eight years.

Matthews told five versions of what happened to Shannon, ranging from being a distraught mother whose daughter had gone missing, to blaming the crime on her former partner Craig Meehan and other members of his family. Donovan, who had convictions for arson, shoplifting and criminal damage, claimed he was terrified of Matthews and was told that he would be killed if he did not comply with her plan.

Matthews and Donovan were branded respectively a "consummate liar" and a "pathetic inadequate" by QCs in court. But it was the contrast between Matthews's distraught media appearances begging for the return of her "beautiful princess" and her actions behind closed doors that particularly struck observers at the trial.

Even the day after she reported Shannon missing, the court heard, she was observed dancing to the mobile phone ringtone of the police family liaison officer who came to see her, and laughing and joking with Meehan.

And when the good news was broken to her that her daughter had been found safe and well, her reaction was to tell the officer in question: "I like the ringtone on your mobile", before going out shopping.

Much has been made of Karen Matthews's social background, at first when commentators complained that Shannon's disappearance was getting less coverage than Madeleine McCann's had because the girl from the council estate in Dewsbury was not middle class. When Matthews's involvement in her daughter's kidnapping was revealed, others were quick to portray her as symptomatic of a malaise in society, focusing on her seven children from five fathers and dependence on state support.

A Tory councillor, John Ward, was forced to resign from Medway council, in Kent, after he used Matthews as an example of "breakdown Britain" while advocating compulsory sterilisation for parents on benefits.

As for Shannon, she was interviewed for seven hours over five days but she was not called as a witness at the trial. The court was told the ordeal had left the girl "disturbed and traumatised" and suffering from nightmares. And when she was asked, after her rescue, whether she wanted to see her mother, her reply was clear: "No."