Clare Montgomery KC, of Matrix Chambers, said she did not believe police “have any interest in prosecuting fraud anywhere”.

Not only were big trials such as the Maxwell pension fraud and Guinness share trading fraud no longer taking place, small cases in which people lose their life savings were being “largely ignored”.

Ms Montgomery, who sits as a part-time judge, said: “You get the occasional show trial in that area. But the reality is that 99 per cent of fraud at that level is not even investigated, still less prosecuted. I’m not saying nothing is happening.

“My concern is that nothing of any substance is happening that would actually deter a professional fraudster or even somebody willing to do dishonest things in the course of business — not necessarily because they’ve set out to be a criminal but because they’re sufficiently selfish and self-interested not to care about the rights of others. Were I inclined to live my business life in that way, I don’t think I’d be very scared of anything that’s available to bring me to book.”

According to official figures, 1,753 police officers and staff dealt with economic crimes such as fraud in 2021, around 0.8 per cent of the police workforce.

This is despite the fact that fraud accounts for 39 per cent of all crime.

Of the five million fraud or computer misuse crimes recorded by people in the crime survey for England and Wales, a mere 50,000 were actually investigated by police and only 4,924 resulted in a charge in 2021-22.

Ms Montgomery laid out her concerns in an episode of the podcast Double Jeopardy, where she was interviewed by Ken Mcdonald, a former director of public prosecutions, and Tim Owen KC.

She said: “Fraud just isn’t that exciting and, insofar as it has excited any interest, it’s mainly at the margins – in areas like proceeds of crime in relation to sanctions; or in relation to occasionally providing assistance to foreign governments.”

“All of that does get attention, and some sort of resources at the investigative level, but in terms of actually having police officers interested in fraud it has been subject to a decline now where I don’t believe they have any interest in prosecuting fraud anywhere.

“The sort of localism that’s been introduced by crime commissioners directing activities by local forces has reinforced that. So now, fraud is absolutely at the bottom of anyone’s agenda.”