A pervert who thought he was enticing a young girl into bed, but was in fact caught up in a newspaper sting, had his prison sentence almost halved today.

The sexual predator used an internet chatroom to sexually groom "Katie", who he believed to be a 13-year-old girl.

But Graham Barnett, 46, was actually talking to a journalist who exposed him as a paedophile after he sent pictures of his genitalia to the fictional girl.

Barnett, of Tulyar Close, Tadworth, pleaded guilty in Guildford Crown Court in February to attempted sexual grooming and was sentenced in March to 30 months imprisonment.

But top judges at London's Court of Appeal have reduced his sentence to 18 months because he was "humiliated" in front of the nation by the newspaper, and because there was no victim, as no child had actually been approached.

The court was told that Barnett initially claimed he was a 17-year-old when he approached "cutekatie93" on a teenage chat site in January last year.

Mr Justice Forbes said "Katie" told him she was 13 and their friendship grew over two days.

The judge said Barnett took "steps to build her confidence" by saying he would like to hug and kiss her, asking: "Do you like older men?" and "How naughty are you?".

When she said she had never tried anything sexual, he said "would you like help?" and that he would not mind if she was inexperienced.

"Katie" was in fact a male journalist from the Sunday People who was asked to examine whether predatory older men were still trawling internet websites.

"Katie" and Barnett agreed to meet at Wimbledon tube station on January 29 last year. The paper's youngest looking female journalist was enlisted to pretend to be the child.

When the pair met, she pretended to be nervous by fidgeting and crying, before saying she wanted to go home.

In a recorded conversation, Barnett offered her McDonalds, told her about his life and hugged her. The judge said he touched her leg and hair "in a caressing motion".

When he asked her back to his house, "Katie" declined but said she would go on their next meeting, which was arranged the following week.

When Barnett turned up to meet her at another train station, he was instead met by the male journalist and the newspaper's photographers.

Barnett ran away and the newspaper subsequently published a story and told police.

Barnett appealed his sentence on grounds it was "manifestly excessive" because of his previous good character, his early guilty plea, his genuine remorse and the effect of exposure in the national press - a "humiliating experience" which led to him taking medication for depression and anxiety.

Mr Justice Forbes said any sexual grooming of a child by a predatory adult was a "very serious matter" which gave rise to a "high level of public concern".

However the judge, accompanied on the bench by Lord Justice Dyson and Judge Rogers QC, nevertheless reduced the sentence to 18 months.

He concluded: "We regard 30 months imprisonment as far too long in the case of a man with previous good character caught by a sting with no actual victim and exposed to very considerable humiliation as a result of exposure in the national press."