Police failed to even identify a suspect in three-quarters of theft investigations closed during 2021 while just five percent resulted in a charge or summons.
Independent charity Victim Support claims the figures undermine public confidence in the justice system.
Home Office data showed Northamptonshire Police closed 14,676 theft probes in 2021. Of those:
■ 76 percent had the outcome “investigation complete – no suspect identified,” up from 73 percent in 2020
■ Another 10 percent of all theft cases were closed because "evidential difficulties prevented further action"
■ Seven percent were closed because the victim dropped the case.
■ No suspect was found in 96 percent of thefts from vehicles, 92 percent in bike thefts and 91 percent in vehicle interference.
Across England and Wales, one million theft offences were closed without a suspect being found, 77 percent of all cases. In London, this was as high as 87 percent while in Norfolk it was 57 percent.
Victim Support said theft can have serious and long-term impacts on victims, robbing them of both their possessions and their sense of safety.
Jeffrey DeMarco, assistant director at the independent charity, added: “The fact that a million cases went unsolved last year seriously undermines victims’ confidence in the criminal justice system.
“Theft is a crime that must always be taken seriously by the police, and work must be undertaken to improve these shockingly low success rates.”
The Liberal Democrat party said its analysis of the Home Office figures shows a “theft epidemic” with over 140,000 car and bike thefts going unsolved by police nationally last year – almost 400 per day.
More than three-quarters of car theft cases and nine in every ten bike thefts were closed without a suspect being identified in 2021.
The Lib Dems said the figures show "criminals are getting away with stealing on an industrial scale” and accused the Government of being soft on crime.
Home affairs spokesman Alistair Carmichael said: "The Government should give forces the resources they need to make sure that every crime is investigated.
“We must reverse years of Conservative neglect that have made our communities less safe and let far too many criminals get away with it.”
In Northamptonshire, 61 percent of cases of stolen motor vehicles were closed with no suspects identified although this was the lowest rate of all nine types of theft.
Northamptonshire Police declined to comment, but the National Police Chiefs' Council said forces will prioritise cases where there is a realistic prospect of prosecution and ensure vulnerable victims have the support they need.
For crimes such as theft, an NPCC spokesman said police focus on targeting prolific offenders, organised crime networks, and ensuring prevention measures are in place.
The Home Office said it is aware of the distress and disruption vehicle, bike and other thefts cause.
A spokeswoman said 20,000 extra police officers are being recruited to protect communities to help prevent these crimes.
Northamptonshire’s police and crime commissioner Stephen Mold recently confirmed the county is on target to have a record 1,500 officers by next year.