The pain of not knowing what has happened to my beloved daughter is like an open wound which has become more agonising every day since she disappeared. There has been no word from Samantha nor a single sighting of her since she left our home on the afternoon of April 3.

It's hard to explain just how much we have suffered in the past few months. While I try not to fear the worst, I feel incredibly guilty that her father and I were not able to protect her from the dangers of the internet. We blame ourselves that we did not supervise her computer use more intently.

Yet, like millions of other parents, we felt it was all fairly innocuous when she signed up for her own web page on the social networking site Bebo which, like MySpace and Facebook, is so much a part of modern teenage life. Many of her school friends are also members and frankly, we thought that chatting to pals online in her bedroom was safer than hanging out with them on the streets.

Both Samantha, 15, and her brother Jack, 13, attend a selective grammar school and they each needed a computer to do their homework. Although I know parents are advised that computers with internet access should be in a communal area of the home, it just wasn't feasible to line up their computers in the sitting room.

Besides, we trusted our children. They've always been sensible and well-behaved and there was no reason to believe either of them would be lured away by a stranger they met online.

Yet, with hindsight, the warning signs were there just after Christmas, when we noticed Samantha was spending more time on the internet. She said she was chatting to friends about homework, but we noticed her attitude began to change. She became secretive, sullen and unco-operative.

I thought she was just going through a stroppy teenage phase. She was still doing well at school and I saw no reason to stop her going out with her friends on Saturdays.

There's not much for youngsters in the small market town of Buckingham where we live, so they would catch the bus into Milton Keynes, 15 miles away, where they liked to browse the clothes shops and go to the cinema, returning home by about 6.30pm.

After one such trip in January, Samantha came home with a bag full of goodies. "Paul bought them for me," she said, showing me her new cuddly toys, makeup and hairbands.

"Who's Paul?" I asked. "A boy from school," she replied and I thought nothing of it.

But the next two Saturdays, the same thing happened and the gifts became more extravagant, so I questioned her more closely about this lad.

Samantha insisted he was 16 and had inherited some money from a relative. But she admitted he wasn't at school with her and she'd met him online after he had sent a message to her Bebo page.

He'd been coming to Milton Keynes to meet her. Alarm bells started to ring. I wasn't happy, but the more I questioned Samantha, the angrier she became.

"He's my boyfriend and I love him!" she insisted. Her hostile reaction was very out of character.

She then began getting calls on her mobile which went on for hours and often left her upset and tearful.

She admitted it was Paul who, alarmingly, would be talking about harming himself over something he thought she had said or done. I told her to hang up and not to speak to him because he was playing mind games.

I was deeply disturbed by what she was telling me - and terrified of the things she wasn't. Desperate for advice, I contacted Parentline and the Samaritans. I was advised to keep a close eye on her, not to over-react and set firm guidelines about when she should be home.

So that's what we did, but Samantha continued to behave oddly. She lost interest in everything except chatting online and on her mobile. If we said anything to her, she'd go into a sulk.

We still hoped it was a temporary phase, but when her school broke up for half-term on Friday, February 9, Samantha announced she was going on holiday to Wales - to stay with Paul. We were horrified. It was a ridiculous, wildly inappropriate suggestion.

Samantha glared at me, shaking with rage. "I've got to go!" she screamed. I repeated that we knew nothing about him and that she was too young to get involved like this.

Tears and tantrums followed and although Samantha gave us an address where she said she'd be staying, we told her quite categorically "No".

Eventually, she agreed not to go. She said she'd go to Milton Keynes with her friends instead, as usual. She'd never lied to me before, so I agreed she could have her Saturday outing.

But the next day, Samantha left the house early, having packed a bag of clothes and her half-term homework. I found out she wasn't with her pals only when I rang her mobile that afternoon and asked her if she'd like a lift home.

"No, I'm in Wales," she replied. I tried to keep calm and told her to come straight home, but she refused, saying she planned to stay for the week.

Worried sick, I rang the police and Samantha was recorded as missing when it emerged the South Wales address she'd given us did not exist.

I was beside myself with worry. She was contacted by the police on her mobile and after a tense few days, she reported to a police station in Bristol with the internet boyfriend in tow.

She'd been staying with him at the home he shares with his father in Bristol. It emerged he was not 16 as she'd claimed, but a 20-year-old unemployed man who had first messaged Samantha on Bebo just after she turned 15.

Samantha insisted she was well, but wanted to stay with Paul and made hurtful allegations against that we were unfit parents, which delayed her return home for several more days.

We wanted to go to Bristol to pick her up, but the police advised us to keep away and that they'd bring her home.

We were mortified. All we wanted was our daughter back, but we had no idea how to deal with this seismic change in her. We barely recognised the defiant stranger who eventually returned to us of her own volition after a week.

Dirty and unkempt, she looked as if she hadn't washed for days. When I tried to wrap my arms around her and tell her how happy I was to see her, she pushed me away. She was so agitated, I was desperately concerned she may have taken drugs. Even more so that she may have been sexually active.

When I gently tried to question her about what had happened, she turned on me. Though she was happy to see her brother, she refused to talk to me or her father.

In tears I rang the Samaritans and Parentline again, but no one seemed able to help. Bob and I didn't know which way to turn. I've never felt so utterly impotent.

We prayed that with patience and understanding, we would get our sweetnatured daughter back. To be fair, over the next few weeks, flashes of our lovely girl did reappear. She went to school and stopped spending so much time on the internet. But every break-time she was seen talking intensely on her mobile and when she came home, she was straight on the phone.

We knew she was talking to Paul. Bob spoke to him on two occasions, each time asking him to leave our daughter alone because we considered the relationship inappropriate.

We pleaded with Samantha to forget about him. She had a wonderful group of friends and a hard-won place at an excellent school. But she remained infatuated. It was as if she'd been brainwashed.

Eventually, on that fateful Tuesday afternoon in the Easter holidays, when Bob, who works for an engineering firm, and I were both at home, we heard Samantha stomp downstairs and out of the front door at 4pm.

We'd had words again about her obsession with Paul and we thought she'd gone to cool off. But when she hadn't returned an hour later, I began to feel uneasy. I tried to call her mobile, but found she'd left it behind.

Nothing had gone from her bedroom - no clothes, no washbag, nothing of note. Yet as I stood by the window looking out for her, I felt a sense of foreboding.

Scared she'd taken off again, I rang the police. Despite her previous behaviour, Samantha had always kept in touch. But this time, there was no word. Though I sat up all night, the next day dawned and she still wasn't home.

Bob and I were desperately worried, and while it seemed likely she would head for Paul's house in Bristol, the police found no trace of her there. He denied seeing her or having any contact with her since before she went missing.

We gritted our teeth, certain that she'd make contact. But several days passed and with still no word from Samantha, we felt as if our lives were in limbo.

As the days became a week and she still wasn't back, the police came to take away her toothbrush in a plastic bag in order to obtain a DNA sample.

After two weeks, she officially became a missing person and hospitals and mortuaries were put on alert.

I was numb with shock and cried constantly. It was hard to understand how she could vanish so completely. And if she wasn't with Paul, where was she?

Had she met someone else online? Had she been abducted by a stranger? She hadn't contacted any family or friends. Though her cash card was in her purse, she didn't withdraw a penny.

It was heart-wrenching to see how badly it affected Jack, who sent desperate messages to Samantha's e-mail address. "Are you alive?" he'd ask poignantly. But there was never a reply.

Soon, a month had passed and it was my 40th birthday. Previously, Samantha had fretted about being away on a school trip that day. As it turned out, I spent my birthday tearfully watching the door, convinced that any minute my beloved child would come bounding in. Devastatingly, it didn't happen.

After that, I couldn't sleep, I couldn't remember what day it was and I didn't eat, quickly losing two stone.

We travelled to places around the country where we knew Samantha had internet contacts and put up posters with her face on pleading for information. The Missing People organisation put out a massive publicity campaign about her.

We fought back tears as we were interviewed on radio and TV, warning other parents of the dangers of internet grooming, but still no one came forward with any news about Samantha.

Because of messages she'd written by e-mail, we were certain our daughter had set out to Bristol - and I began trawling the websites she'd used, searching for more clues.

I found e-mail conversations which proved how Samantha had been wooed by her boyfriend with flattering talk and a series of film clips using her pictures.

I was stunned as her face popped up over and over again, interspersed with messages which declared undying love for her. "I can't live without you" and "I will never leave you, ever" they proclaimed, as cheesy romantic songs played in the background. It was stomach-churning.

I could see by the dates the pictures of Samantha were posted that it started in January. Suddenly, I understood why she had changed. As I made contact with other young girls online who'd had similar experiences, I realised how dangerous these social networking websites can be.

A man of 20 grooming a schoolgirl is every bit as dangerous as a 40-year-old, if not more so, because the girls are flattered by the attention of a young man they instinctively see as a possible boyfriend and not an abuser.

Anyone can join these sites and influence young minds. I am shocked by the lack of policing - so many young girls, some just 13 and 14, post provocative pictures of themselves and even display their phone numbers. It is surely a sexual predator's paradise.

If only I'd known all this before, I would have insisted on Samantha's computer being in the front room despite her protests. Now, all I can do is pray that she is out there somewhere reading all the messages that we and her friends have posted for her. Every day, I write something on a web page or forum, begging her to come home, saying we love her no matter what.

Each day without her is like an eternity. With a younger child, you can keep them in and watch over them. You can't keep a teenager with you all the time, but their loss is every bit as painful.

While we still feel Samantha set out for Bristol when she left, with no confirmed sightings since, she could be anywhere.

Paul still insists he's not seen her, so we don't know if something terrible happened to her on the way to see him, or if she was groomed by someone else.

But whatever has happened, the fact is that our nightmare all started with internet grooming. If she hadn't first been seduced in a chatroom by Paul, she would still be with us.

Our beautiful girl may never come home, but by telling our story I hope that other parents will take note of the dangers their children face every time they log onto a social networking site.

Please watch over them - or they may disappear, like Samantha did.

Labels: bebo, disappearance, predator, samantha osborn, seduced online