Like the appearance of slimy blue algae on a pond, the presence of Christine and Neil Hamilton on a TV show is a reliable environmental indicator. One just knows that, beneath the surface, something not quite right is going on.
It is not that they are dishonest - they are simply earning a living as best they can. When they emerged, battered, defeated but famous, from their legal tussle with Mohamed Fayed, the Hamiltons made a career decision so reckless that it bordered on the heroic. They would make being celebrities their career. Others have tried to do the same - the girlfriend of the briefly notorious John Leslie now presents a show on cable TV, Beckham's bunk-up Rebecca Loos is to be seen every night flirting with Stan Collymore on Five's enjoyable The Farm, and there are even rumours that Nancy Dell'Olio has showbiz dreams. But these people have advantages of looks and age that are not shared by the thoroughly ordinary middle-aged couple that is Mr and Mrs Hamilton.
Yet the public service that they offer - that of unwitting tackiness detectors - is often useful, as has been proved yet again this week. Neil and Christine have agreed to present a quiz show on Five called The Great Big Giveaway Show, which appears to be a sort of cross between Family Fortunes, Beadle's About and Crimewatch. Here's the set-up: carefully selected members of the public are offered the chance to appear on TV and to compete for big cash prizes. Not only will their hosts be the Hamiltons, but another lower-alphabet celeb called Darren Day will be doing the announcements.
What the contestants will not know, but the audience will, is that they have been chosen for one particular reason: they have all failed to pay a fine or answer a court warrant. The show, in fact, is an elaborate, and very public, police sting.
It is the boys in blue who select 20 of the juiciest cases to appear on the show. The contestants are frisked at the door by a man in a dinner jacket - another rozzer, of course. After they have been made up, they will step out in front of the cameras for their big moment, be greeted by Christine and Neil, and then nicked. Of the 20 contestants, we are told, eight were wanted for outstanding fines and nine for a range of offences from traffic violations to skipping bail. What the remaining three, who are presumably innocent, make of appearing on the show has not been disclosed.
It will probably make marvellous TV, watching these minor league wrong 'uns breezing cheerfully on stage to have the smiles wiped off their faces, and all in an excellent cause. As a man from the Hampshire Police put it: "This operation sends a clear message to those who are wanted that we will use any lawful audacious tactics to bring them to book."
Of course it does, and doubtless the fact that these lawful audacious tactics provide good publicity for the police and a profitable show for Five is entirely irrelevant. All the same, there is something faintly alarming about the increasingly close - and entirely unquestioned - partnership between the forces of law and those of entertainment. The dividing line between fiction and reality has, over the past three or four years, become generally blurred on TV and in films, but nowhere more so than in the coverage of police work.
Crime has always been a staple ingredient of popular entertainment; now both the media and the police themselves have realised that real wrongdoing and the nabbing of genuine villains add a new edge to the fun. A Crimewatch culture has seen a new and largely prurient public interest in police work.
On the night when a verdict is expected on our most lurid and exciting murders, TV channels race to air their own inside account of the investigation. True-life tales of murder and violence compete on late-night TV with low-budget recycling of police videos capturing car chases or fly-on-the-wall documentaries following police operations.
On the whole, these programmes provide publicity of a relatively harmless type. Among the police officers whose work is followed, there is no place for the bungler, the thicko or the fit-up merchant. Whether they are brilliantly piecing together evidence or dealing with unpleasantness that the rest of us avoid, the police are presented, and cheerfully present themselves, as heroes.
It would take an unusually virtuous and strong-minded group of individuals not to be influenced by their new role. Too often, when a policeman appears at a press conference or is interviewed at the scene of some ghastly crime, one is left with the nagging sense of someone enjoying his role centre-stage rather too much.
Who could be surprised? When it is regarded as a lawful, audacious tactic to entrap suspects as part of a TV game show, then inevitably police work itself will become more of a media activity, and officers will be tempted to swagger about self-consciously as they pursue their investigations.
Maybe one should not fret too much about such things but, in a society that has becoming increasingly concerned about its security, there is something mildly unhealthy about a police force that now has its own propaganda wing within the ranks of the mass media.