It is worrying enough that a newly elected Police and Crime Commissioner should be spending £700 on a chauffeur-driven Mercedes – even more so given growing complaints of cronyism and waste by PCCs. But what is more alarming still is that three people have been arrested for leaking Richard Rhodes’s inflated expenses to a newspaper.

Rather than being arrested, the three civilian police workers should be publicly commended. Had they not acted, Mr Rhodes’s self-indulgence would have remained hidden, leaving the public purse to bear not only this particular extravagance but any number of future excesses as well.

It is not difficult to see how the Cumbria force could get carried away in the aftermath of the phone-hacking scandal. After all, Operation Elveden – set up to investigate allegations of the widespread bribery of public officials – has resulted in some 60 arrests so far, the vast majority of them journalists and police. One former chief inspector has been sent to jail.

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But there is a clear distinction to be drawn between a police officer sharing confidential information for money, kudos or any other perk, and a whistleblower – police or otherwise – who breaks ranks in order to draw attention to matters of safety, inappropriate behaviour or the improper use of public funds. For all the wrongdoing revealed in recent years, the “public interest” defence remains as fundamental, and as justifiable, as ever. And Cumbria is surely an unambiguous example of it in action.

There is also a wider point here. Reporting of suspected wrongdoing is lamentably rare in Britain in comparison with the US. Too often our institutions make it harder. It took the recent high-profile case of Gary Walker – the former head of a hospital trust who risked having his £500,000 pay-off withdrawn after he raised concerns about patient safety – for NHS staff to be given the legal right to go public about care issues.

Britain needs more whistleblowers, not fewer. The Cumbria arrests are a step in the wrong direction.