By Nick Higham BBC culture correspondent

A woman is acquitted on serious criminal charges. The judge at her trial expresses unease at payments promised to witnesses in the case by tabloid newspapers.

The government, it emerges, is promising a "crackdown" on such payments.

There is something wearily familiar about the aftermath of the Amy Gehring trial.

Several of the teenagers who gave evidence at her trial were offered sums of up to �10,000 a time for their stories by five newspapers: the News of the World, the Sunday People, the Daily Mail, Mail on Sunday and Sunday Mirror.

Protests

Judge John Bull QC warned jurors that offers of money may have prompted the teenagers to exaggerate their stories.

The judge at the Gary Glitter trial expressed concern

Now it seems the Lord Chancellor, Lord Irvine, is to publish a consultation paper on whether payments to witnesses in criminal trials should be banned.

And the Labour MP Clive Soley, a long-standing scourge of the tabloids, has written to the Press Complaints Commission to protest about the payments.

We have been here before.

The last time the issue surfaced was just over two years ago when the pop singer Gary Glitter was acquitted on charges of sexually abusing a woman now in her 30s when she was just 14.(he was convicted of possessing more than 4,000 pornographic images of children taken from the internet).

The woman had sold her story - more than once - to the News of the World, though its most recent offer to pay her had been made before the paper knew she was to be a witness at the trial.

The judge in that case called the arrangement "a clearly reprehensible state of affairs".

Investigation

Following pressure from a committee of MPs, amongst others, the government at the time set up an "interdepartmental group" to look into the problem.

Before that there was the consultation paper issued by a previous Lord Chancellor, Lord Mackay, in 1996 in the wake of the Rose West trial.

Though West was convicted the Attorney-General at the time, Sir Nicholas Lyell, expressed his worries that payments to witnesses could have prejudiced the trial.

But even before Lord Mackay issued his consultation paper, worries about the practice had led the Press Complaints Commission to tighten up its code of practice.

Accounts from the West trial were sought after

The code now bans payments to witnesses or potential witnesses in current criminal proceedings "except where the material concerned ought to be published in the public interest and there is an overriding need to make or promise to make a payment for this to be done."

Editors must be prepared to demonstrate what that public interest is, and payments must be disclosed to the prosecution and defence.

The issue was hardly new even then. The most notorious case of a trial supposed to have been tainted by payment to a witness was that of Jeremy Thorpe, the former Liberal Party leader, in the 1970s.

He was acquitted on a charge of conspiracy to murder when it emerged that the chief prosecution witness, Peter Bessell, had been paid �10,000 by the Sunday Telegraph for his story - with a promise of �25,000 if Thorpe was convicted.

Before that, in 1974, a committee on contempt of court had suggested an investigation of payments to witnesses with a view to possible legislation.

And in 1966 the Attorney-General of the day promised an examination of the law after allegations that a prosecution witness in the trial of the Moors Murderers, Ian Brady and Myra Hindley, had been paid a retainer by a newspaper, with the promise of more cash on conviction.

Press freedom issues

The fear has always been that an offer of a fat cheque from a newspaper will cause a witness either to exaggerate his or her story or to hold back some of the juicier titbits for later publication.

But successive Lord Chancellors and Attorney-Generals have failed to find a way of legislating to prevent that kind of undesirable outcome without seriously hampering newspapers' legitimate freedom to report.

And the newspapers' apologists argue that the prospect of payment for their stories actively encourages some witnesses to come forward.

A spokesman for the Lord Chancellor's department says each case is different and raises different issues, which is why there is a need continually to revisit the problem.

But the temptation is to see the succession of consultations and committees of inquiry established over the past 30 years simply as time-honoured civil service delaying tactics.

Faced with public concern over an intractable problem, the simplest solution is to buy time with a consultation exercise that is little more than window-dressing.

Maybe this time there will be legislation. But don't hold your breath.