Naturally, no such issues could ever arise in Australia, although it is instructive, just in case, to see how other systems work, and what happens when inappropriate conduct comes to attention.

Mr Cruddas, charged with party fundraising in the face of efforts to increase the transparency of the process, was offering levels of participation of "clubs" of Tory sympathisers.

Team 2000, for example, consisted of people contributing £2000 a year to party funds. The top group in the seven-tier system were in the Leader's Group, paying at least £50,000 a year. Members of the latter were, in the words of the party brochure, "invited to join David Cameron and other senior [party] figures ... at dinners, lunches, drinks receptions, election result events and important campaign launches."

Mr Cruddas, in discussions with people he believed to be potential donors, put the access and the promises a bit higher than that. At such functions, you could "get to hear a lot of things," ... "key bits of information that you can use ... when you see the prime minister ... you will be able to ask him practically any question you want".

The conversations were videotaped. The primary judge – a man very confident about his ability to do his duty and able to rise above his impeccable family connections to the party, found that any innuendo of corruption was entirely wrong, unfair, and awarded Mr Cruddas swingeing damages for such an dreadful imputation.

But three judges of England's Court of Appeal have recently concluded, after listening to the tapes, that Mr Cruddas was very definitely giving an impression that if people donated large sums of money to the party they would have an opportunity to influence government policy and to gain unfair commercial advantage through confidential meetings with the prime minister and other ministers.

Though Cruddas was not suggesting any type of criminal offence under the Bribery Act, what he was proposing, as Justice Jackson put it, was "unacceptable, inappropriate and wrong."

To be sure, Cruddas would religiously say, from time to time, that one could not "buy" access, the party or decisions from its officials. But he would then go on to say things that contradicted this. Lawyers for Cruddas begged the judges to pay attention, as the primary judge had done, to the exculpatory statements, and submitted that when there were both inculpatory and exculpatory statements, the exculpatory statements should prevail. Lawyers against him said such inculpatory statements should not have been there in the first place, and the Court of Appeal agreed.

Poor Mr Cruddas had been trapped by lying journalists. They were using techniques one might never see in Australia, least of all now that our communications are under the benevolent supervision of ASIO, the Australian Federal Police, state police forces, the RSPCA and miscellaneous pest and noxious weed inspectors. We are given to understand that any operations involving the scrutiny of journalists will be rigorously monitored for adherence to the public interest, but one can hardly expect any outbreaks of adventurism in these straitened times when lawyers cost money that is no longer there.

Journalists in Britain, and in the United States are using undercover techniques, long used by journalists in Europe, of what might be called integrity tesystem's

In recent times, for example, two very prominent British politicians, Jack Straw (Labour) and Sir Malcolm Rifkind (Tory) were sounded out by undercover journalists pretending to be representatives of a Chinese firm about whether they would be "consultants" on an advisory board as their company sought to expand its business in Europe.

Both were very keen on the idea, and the idea of payments in the realm of £5000 a day. Jack Straw, like Rifkind a former foreign secretary, boasted that he had previously used his influence "under the radar" to help change European Union regulations on behalf of a commodity firm that paid him £60,000 a year.

He also claimed to have used "charm and menace" on behalf of that firm in order to persuade Ukraine politicians to drop a law hindering the firm's operations.

Rifkind, who now oversees Britain's intelligence operations on behalf of parliament, said that he would submit questions to ministers without "naming who was asking", complained that he "had to earn my income" and boasted of his enormous range of contacts, implicitly for sale to anyone who put him on the payroll. He said he could, for example, quickly arrange to meet any ambassador he wished in London.

It was a most unattractive picture of the great and good in another country. Here, we are regularly assured by politicians, judges, police and officials, standards of integrity are much higher. So high, in fact, that we do not need to have any systems of making sure.

Here, such deceptive investigative conduct is prima facie unethical, even by the standards of the profession. At least when directed against the great and good – cops or politicians, for example – it is also probably illegal. (Here, the first response of the AFP to a Cruddas matter would be to mount an investigation of the journalists for illegally taping a conversation.)

If deception were to be justified, either as ethical conduct by the local standards of journalists, or in a court, it could escape only if it were manifestly in the public interest. Such is the general antipathy of judges to journalists (in part because of how Murdoch journalists have abused the public interest over the years in Britain) the public interest bar is set very high.

In my opinion, for example, it never justifies the cheap exposure of dodgy tailors, repairmen or car dealers on "infotainment" current affairs shows. I can think of any number of judges who would always think that any mongering of doubt about the integrity of the judiciary, the legislature or the executive was against the public interest, come what may.

In my opinion, the public interest, would probably have to embrace clear indications, before any undercover operation, that the victim was already doing what would later be alleged. One would also have to use extreme care – much more than police ever show, or the judiciary permits – about entrapment.

The nagging problem, for journalists, is the fundamental difficulty of using deceit to tell a truth. It is one that, in my opinion, must always be resolved, if it can be, only by complete frankness with readers about what happened, what deception was used, and why. That must be an explanation that stands up in advance of, not in arrears of, the deception.

Naturally enough, not all deception operations are focused on how public officials, people in positions of public trust, and great and powerful people influence and are influenced by others. Tabloid journalists are as interested in stinging film stars, TV starlets, models, and football players, and the subject matter can involve a fondness for drugs, for adultery, for gambling, or, generally, for a hypocrite doing something of which they have pretended to disapprove.

I expect, one day, that the 7.30 report will use infra-red cameras, metadata and undercover operators to prove, in the public interest, that a prominent chef uses meat scraps to make gravy.

In Britain and the US, police inspectorates, the FBI and various crime and integrity commissions have regularly used elaborate scams to detect officials on the take. Among those caught in targeted operations have been judges, federal, state and local government politicians, and public servants at all levels of government.

Such operations have also targeted people in business, in the lobbies, lawyers, brokers, middlemen and fixers, and organised crime. Some of the operations, such as ABSCAM, have been the subject of movies.

In the US in particular, the amazing thing is not usually how venal and susceptible to bribery and favours so many people are, but how cheaply their honour can be bought and sold. A person who does something contrary to duty for $50, for example, has put a low value on their right to their job, reputation, and right to respect from their children and neighbours.

Any number of students of the corruption culture have written of the rationales and excuses, not least the claim that everybody does it, but nearly everyone who does remarks that the incidence, prevalence and acceptance of culture is a simple calculus between the chance of getting caught and the disgrace or punishment one suffers if one is caught.

It really helps if no one is looking hard, and no one anyway is tasked with looking. This is the Australian national and territorial model. There are bodies in most of the states, such as ICAC, tasked with catching corruption brought to their attention, but Canberra, in whatever form, has no need of such things.

Strictly, one might argue that the AFP, and, in a secondary way, the Directors of Public Prosecutions, are the ones we rely on to stop bribery, corruption or criminally negligent stewardship of the public estate. But the AFP is complaints-driven, not proactive in searching out crime, and, in any event, without a culture, a professionalism or training up to the task. It has also suffered from politicisation, which makes it unlikely to bite the hand that feeds.

Even by comparison with lack-lustre (and hardly corruption-free) state police forces, the AFP is up to 20 years behind Britain and the US in its order of battle and doctrine. It is rather more active in searching out crimes involving drugs or terrorism, and in arranging, by rewarding and punishing compliant journalists, fabulous publicity for its successes and (especially) senior officers. But the public has few means of testing confident police statements about the effect of their activities on whatever crime is being "fought."

There is no evidence that 40 years of dedicated and expensive police and customs activity against illegal drugs has had the slightest serious influence on supply, despite some big seizures. It has certainly had no impact on demand. Moreover the "war against drugs" has not increased, but diminished law enforcement integrity, professionalism and public confidence in a corruption-free guardianship of the law.

The odd Australian royal commission, most notably the Wood Royal Commission into NSW Police, have experimented with integrity testing (remember "Chook" Fowler?). The Australian Commissioner for Law Enforcement Integrity claims that it does, if only on cops and customs officers, from time to time. But, judging by the annual reports, only minnows, and even them few, swim in the federal stream.

Either federal law enforcers are amazingly pure, or, more likely, efforts to catch rotten apples are naive and inept, and hardly ever likely to get a result involving anyone of above the rank of constable. One suspects that a big catch, were there ever one (there hasn't been yet, by ACLEI anyway) would be suppressed in the public interest, lest, for example, it undermine public confidence in the AFP, or the new paramilitary Customs and Border Protection Service.