The 'scoop', the superstars and the collapsed trial

For the editor of the News of the World, it could hardly have come much better. The opportunity to reveal ­ and prevent ­ a £5m plot to kidnap the wife of the world's most famous footballer. Exclusive pictures of the "murderous kidnap gang", spreadeagled on the ground as armed police rush in to arrest them. A grateful potential victim, a superstar in her own right, thanking the paper and its star reporter "for everything you've done" in averting such a horrible ordeal.

The Beckham exclusive will have done no harm at the time to Rebekah Wade ­ then at the helm of the News of the World. Her proprietor, Rupert Murdoch, was to move her to his most high-profile British posting, the editorship of The Sun, just two months after the explosive story.

Since alighting at the daily paper, she has injected a saucier, riskier formula into the paper, making The Sun noticeably more mischievous than under her predecessor David Yelland. And as if she even needed it: some of the alleged kidnappers turn out to be asylum-seekers. What more could Ms Wade ask for?

Who could match her sensational front-page story on 3 November last year: "World exclusive: We stop crime of the century"?

Alas, some stories are too good to be true. Yesterday, the trial of five men accused of plotting to kidnap Victoria Beckham collapsed ­ with the judge saying that he would refer the News of the World to the Attorney General "to consider the temptations which money being offered in return for stories, in particular about celebrities, gives rise to and the way in which newspaper investigations may have a detrimental effect on ultimate court proceedings.

The case, at Middlesex Guildhall Crown Court, was thrown out after the Crown Prosecution Service said the evidence of its central witness, a criminal who had been paid £10,000 by the newspaper, was unreliable.

The court had heard that Florim Gashi, who has convictions for dishonesty, had infiltrated the gang on behalf of the newspaper. A CPS source, speaking outside court, said: "We are now of the opinion that he is an unreliable witness after receiving financial gain from the News of the World."

The case has thrown light on a world usually hidden from even the most scrupulous readers of the red-top scandal sheets. At the centre of events, as is so often the case with the News of the World's sexiest stings, was Mazher Mahmood, the paper's investigations editor.

Mr Mahmood, one of the News of the World's stars, revels in his reputation as a man of mystery. His face is never shown in the paper, nor does he venture out to media parties. The sometime "fake sheikh" had been given permission to give evidence in this trial from behind a screen in order to protect his identity from those seeking revenge among the many child molesters, people smugglers and gun runners he has turned over to the police in his career.

Mr Gashi had passed information to Mr Mahmood in the past, and had been paid for his efforts. Claiming to be battling for law and order, he seems to have acquired a taste for forwarding crime tips to the paper. So he approached the News of the World with details of a robbery plot.

But Mr Mahmood was not interested. The tale he was offering was not big box office for the News of the World. According to Brian Altman, for the prosecution, it was only "when it was made clear to him the story would not sell newspapers" that Mr Gashi came up with a better tip ­ that a plan was under way to kidnap Victoria Beckham, sedate her with a chloroform-type spray and hold her hostage in a house in Brixton, south London, until her husband, David, paid a ransom of £5m into a foreign bank account.

It now appears that Mr Gashi may have planted the whole idea of the alleged kidnapping plot among his supposed co-conspirators. "There was no independent objective evidence that the plot to kidnap Victoria Beckham was raised by the defendants rather than Gashi himself," Mr Altman said.

Penny Muir, solicitor for Alin Turcu, 18, one of the men acquitted, told The Independent: "My client was drunk, he thought the whole thing was a joke. They were all playing along with Gashi."

Mr Turcu has spent seven months in Feltham young offenders' institution as a result of the tabloid sting, she said."Right from the beginning, the police were bounced into this prosecution by the News of the World ...When I was called into Charing Cross police station on the Sunday morning, I had the odd experience of having to tell the police what had been in the newspaper and what was going on. I am outraged. It is a scandal this prosecution was driven by the priorities of the press."

If the accused are angry, so are the police. In the paper's original report, a senior officer was quoted telling the News of the World: "You've done a fantastic job." But it emerged in court that the first time police knew that the Beckhams were potential targets was on the morning of 2 November ­ just a few hours before the News of the World had arranged for the gang to turn up in a hotel car park.

"Because the investigation was handed over to police on the day of the arrests, the processes and procedures ordinarily adopted by a professional police operation were not in place ... at any time during the evidence-gathering stage," Mr Altman said. Consequently, the prosecution team had little to rely on beyond Mr Gashi's testimony.

Mark Stephens, a media lawyer, described the role of the tabloid newspaper as "deplorable". He said last night that the payment of witnesses by newspapers was a major problem. "It may be that the only way of resolving it is by legislation, I am sad to say. At the root of all this is the tainting of information."

This is not the first time a cheque from Fleet Street has caused concern in legal circles. Last year, during the trial of a teacher, Amy Gehring, accused of having sex with under-age boys (she was acquitted), three prosecution witnesses were offered thousands for their stories.

The phrase "chequebook journalism" entered the language 20 years ago, after the 1981 trial of the Yorkshire Ripper, Peter Sutcliffe. But the phenomenon had been in existence for decades. In 1966, the chief prosecution witness in the trial of Moors murderers, Ian Brady and Myra Hindley, was criticised by the judge for entering into a deal with the News of the World.

At the trial of the former Liberal leader Jeremy Thorpe,in 1979, a key witness, Peter Bessell, was offered one of the most notorious deals in Fleet Street history ­ The Sunday Telegraph offered to pay him £25,000 if Mr Thorpe were found innocent, but £50,000 if the jury declared a guilty verdict. Mr Thorpe was, of course, acquitted of conspiracy and incitement to murder.

Such payments are not illegal ­ though they are in contravention of Press Complaints Commission (PCC) guidelines that came into effect four months after the News of the World's kidnap story. The PCC code bans payment or offers of payment to witnesses or potential witnesses once a suspect has been arrested. In cases where nobody has been arrested but is likely to be, payments can be made where there is a "demonstrable public interest".

Sir Christopher Meyer, chairman of the PCC, yesterday said: "The rules on witness payments have been considerably toughened since the News of the World broke this story. The PCC will act in any case where a newspaper or magazine is found ... to have breached them."

Last night, the News of the World issued a defiant statement expressing "surprise" at the decision to drop the case against the five men.

"We fully stand by the report published in the newspaper in November last year. The story resulted from a thorough and legitimate investigation undertaken by one of the paper's most senior and experienced reporters ­ a journalist responsible for more than 100 successful convictions.

"Since November we have co-operated fully with the police leading this inquiry, passing on all evidence. That included all information about Mr Gashi. No information was concealed or held back. Indeed, the police thanked the News of the World for our full co-operation."