Image caption Karen Matthews came out of her house to talk to Mark Simpson

Shannon Matthews's disappearance in a 2008 hoax-kidnapping is being recounted in a BBC drama. BBC News's Mark Simpson, who reported on the case, looks back at the deception.

Karen Matthews made a fool out of me.

I looked into her sunken eyes, saw that she was petrified and gave her the benefit of the doubt.

Maybe my judgement was coloured by the fact that she chose to give me her first interview.

Maybe it was clouded by seeing inside her small semi-detached house, and the grim conditions in which she and her seven children were living.

Maybe I was so cold at the time, my brain froze.

Karen's daughter Shannon, nine, disappeared on the coldest night of the year in February 2008.

Image copyright PA Image caption Shannon was missing for 24 days

Police divers who searched a lake near her home in Dewsbury Moor in West Yorkshire had to break through ice to get into the water. The air temperature had dipped to -4C.

The night Karen agreed to talk to me, I was shaking with cold after spending hour after hour talking live on the BBC News Channel (or BBC News 24 as it was then).

Karen spotted me out of her front window and came out to talk. She was shaking too, but out of fear.

She was scared - scared of being found out.

She gave me no eye contact. She looked down the barrel of the BBC camera and said; "Shannon if you're out there, please come home. We love you to bits, we miss you so much. Please, I'm begging you baby, come home."

Image copyright PA Image caption Karen Matthews appeals for information on her daughter's disappearance

When the police saw her interview on the BBC Ten O'Clock News, they were annoyed.

They had advised her not to talk to the media. They were as surprised as me that she agreed to give me an interview.

So was this erratic behaviour the first sign that all was not what it seemed?

In hindsight, it may seem so, but at the time, it seemed simply a desperate act by a desperate mother.

Fresh in my mind were the Soham murders of schoolgirls Jessica Chapman and Holly Wells. When children disappeared for more than 48 hours, the outcome was usually not good.

That is why there was such a huge community effort to try to find Shannon. People realised that time was short.

Yes, I did wonder if Karen Matthews was telling the truth. Everyone did.

However, I believed her. And I was not alone.

Image copyright PA

As well as searching hedges and parkland, the police drew up a map showing where convicted paedophiles lived in the Dewsbury area.

They checked, and double-checked. There was no sign of Shannon.

As days turned to weeks, the more convinced detectives became that Shannon would not be coming home.

However, Karen's friends and neighbours never gave up, and neither did the police.

About 10% of the force's officers were put on the case and more than £3m was spent in what was one of the largest search operations since the hunt for the Yorkshire Ripper.

Image copyright Getty Images Image caption Karen Matthews was jailed for eight years

Shannon was eventually found, 24 days after she disappeared. A BBC colleague got a tip-off and phoned me.

I was shopping in Ikea in Leeds at the time, and nearly dropped my phone on a multi-coloured Swedish rug when I heard the news.

As I drove down the A6110 to Dewsbury, I wondered if Karen would give me an interview again.

We could do it in the same spot where we had first spoken.

The only difference would be that this time she would be with Shannon beside her.

The tears would turn to cheers. For once, it would be a story with a happy ending.

What a fool I was.

It later emerged that Shannon had been kept drugged and hidden in the base of a divan bed by the very people appealing for her safe return.

That September Karen, and Michael Donovan, the uncle of Karen's partner, went on trial for kidnap, false imprisonment and perverting the course of justice. They were jailed for eight years after the court heard about their plot to hide the child and claim a £50,000 reward that subsequently had been offered by the Sun.