IT is a romantic story that has caught the imagination of 13,000 people around the world.

When web designer Keir Moffatt missed the chance to ask out a beautiful girl on a train to Bristol, he tried social networking website Facebook to see if he could track her down.

In little more than 10 days, the story of his missed connection had spread to the US, Australia and Malaysia, with thousands of followers wishing him well.

Mr Moffatt, 26, who lives in Durdham Park, was travelling home from Cardiff at about 7pm on Thursday, May 6.

On the train he saw a girl with a blue hair band.

He said: "She was in the same carriage as me and just gorgeous – really unique looking. I was sitting there thinking 'talk to her', 'do something' so in the end I asked her a question about the train and we had a short conversation. Afterwards I really regretted not talking to her more and when my mate picked me up I had a rant about not plucking up the courage to ask her out for a drink."

Using the theory of six degrees of separation Mr Moffatt, who is also a breakdancer, decided to set up a Facebook group to see if he could find his mystery girl.

Within 24 hours about 1,000 people had joined the group and by Saturday it was approaching 2,000.

It was then the former UWE student decided he could use the group to help raise funds for charity.

He said: "I was completely overwhelmed at the numbers of people signing up and so I created a video to thank people. There was an element of all the attention that was quite embarrassing so I thought it would nice if something better came of it.

"My sister works for Marie Curie, a lot of my family and friends have been affected by cancer so I thought it would be nice for people to donate £1 or something."

The appeal struck a chord with followers and numbers increased to 8,000.

"It was that point that I thought it was getting out of control", he said. "I was worried that there was potentially a lot of attention that would be directed towards the girl even though I'd been quite vague about her description. I had a few messages from people saying it was them but I had no idea if they were real or fake."

But the decision had the reverse effect with more than 13,000 followers adding to the £800 raised for Marie Curie.

"People were telling me not to give up," he said. "I think men can all relate to a time when they'd wished they'd spoken to someone and perhaps women have an insight into how difficult men find it. It's a bit weird and I was worried it's a bit stalker-ish but it's about wearing your heart on your sleeve.

"I'm OK that the girl remains a mystery. I want to apologise if any of this caused any trouble for her. It was just a bit of fun. If she hasn't seen the group and doesn't think I'm a complete weirdo then it would be amazing to go for a drink with her after everything that's happened though. I'll definitely make sure I don't miss a chance like this again."

To donate visit www.justgiving. com/mysterytraingirl.