The area is bucking the trend across England and Wales, where the number of cases has dropped by nine per cent in three years.

Legal experts say the police don't have enough resources to complete investigations to the standard required by the Crown Prosecution Service, leading to cases being shelved.

New Ministry of Justice data shows that 40,057 offences reported by West Mercia Police led to a prosecution in 2018 – 57 per cent more than three years earlier.

Of those, 21,280 proceedings were summary motoring offences, such as speeding and driving whilst disqualified, up from 10,421 in 2015.

Summary offences are less serious, and are usually dealt with in Magistrates' Courts.

A further 13,087 were summary non-motoring, such as TV licence evasion and less serious criminal damage, compared to 7,957 in 2015.

Among the more serious prosecutions, the biggest chunk in West Mercia were related to theft offences with 1,698 cases in 2018, compared to 2,214 three years previously.

There were 780 proceedings related to drugs, while a further 1,030 prosecutions were due to physical assaults.

The number of individuals prosecuted or given an out-of-court disposal is the lowest since 1970 in England and Wales, with 1.59 million individuals dealt with in 2018.

For Dyfed-Powys Police, 8,754 offences ended up in prosecution in 2018 – 40 per cent fewer than three years earlier.

Of those, 4,925 proceedings were summary motoring offences, such as speeding and driving whilst disqualified, down from 7,955 in 2015.

A further 1,405 were summary non-motoring, such as TV licence evasion and less serious criminal damage, compared to 3,371 in 2015.

Among the more serious prosecutions, the biggest proportion in Dyfed-Powys were related to theft offences with 654 cases in 2018, compared to 736 three years previously.

There Were 536 proceedings related to drugs, while a further 427 prosecutions were due to physical assaults.

Crumbling

Christina Blacklaws, president of the Law Society of England and Wales, said the statistics come as no surprise when the police, Crown Prosecution Service (CPS), courts and defence lawyers are so significantly under-resourced.

She said: "Our criminal justice system is crumbling, and it simply does not have the capacity to function effectively.

"Solicitors often report delays from the police in preparing and taking statements, and the CPS in reviewing evidence and deciding upon the charge.

"To deal with this problem, police forces are increasingly releasing suspects under investigation - often with no time limit to complete the investigation and bring the case to court.

"This means cases can be delayed for an indefinite period before going to trial if they do at all. We know in some cases, this has left both victims and the accused waiting for up to two years for an outcome."

Rick Muir, the director of the Police Foundation think tank said that budget cuts are behind the national fall in case numbers.

He said: "If you have 20,000 fewer police officers today than in 2010-11, then fewer crimes will be solved and fewer will end up in court. Recorded crime has been increasing in recent years, so if the number of offences being tried in court is lower, that tells us that the police are clearing up fewer."

In West Mercia, sexual offence cases were prosecuted 367 times, 202 fewer than three years earlier.

Mr Muir added: "Sexual crime takes longer to investigate than average because of its complexity, but this trend is also down to having fewer police officers."

Commenting on the figures, a spokesman from the Ministry of Justice said: "Under this government the most serious offenders are more likely to go to prison, and for longer.

"Criminals are also being convicted at the highest rate for a decade, helping protect the public and keep communities safe.

"Sentencing is a matter for independent courts, who take into account the full facts of each case."