There’s plenty of coverage today for perhaps the least surprising story since it turned out Gordon Brown wasn’t a very nice man: it is now official that police crime figures are fundamentally unreliable.

Anyone could have told the UK Statistics Authority this. People have long known there is more crime than the official figures record – and on this, just as in other areas, their suspicion of the official picture has been proved correct.

Many people have personal experience of the problem. Take this example, told to me by an impeccable correspondent:

Climbing out of her car for a few seconds to access a pay-and-display machine, she returned to find her handbag gone from the passenger seat. Obviously it had been stolen. She reported it to the police, who then said it couldn’t be registered as a crime as she hadn’t actually seen someone take it. Therefore, the officer explained, she wouldn’t be given a crime number, but could have an incident number if she needed it for insurance purposes.

Later that day, a good Samaritan phoned her house – they had found her handbag, emptied of cash and bank cards, while retrieving their football from some shrubs in a local park. With the evidence that she had been robbed, and that her bag hadn’t walked off under its own propulsion, she rang the police again. Ok, they conceded, it was a crime. Here’s the crime number for your street. Er, what do you mean for my street? Ah, it’s just the crime number we use for all the residents of your street rather than issuing a new one each time something happens. Saves on paperwork, you see?

The process was clear – if possible, the police refused to register crimes as having occurred. If the proof was indisputable, then they registered them all under a number for the whole street – thus keeping the official statistics down.

This happened about ten years ago, so the process may well have changed since. But it is a stark example of how unreliable police statistics are, and of some forces’ willingness to manipulate the numbers.

It’s good news that these failings are finally being confessed and confronted – for too long officialdom has been content to live a statistical lie, and to allow some parts of the police to operate in a manner which is essentially dishonest.

Importantly, contrary to some media reports today, this doesn’t affect the fact that crime in the UK is down. The British Crime Survey, which in no way relies on these flawed police data-gathering methods and was set up specifically to bypass them, independently confirms that the number of crimes people suffer is falling.

However, the dishonesty and incompetence which undermined the official police statistics means that ministers will now have an even harder job of persuading voters of their success, unfair as that may be.