One in five crimes were found to be recorded incorrectly by police in South Yorkshire during an inspection.
An interim report by HM Inspectorate of Constabulary said there were ‘serious concerns about the crime-recording process’ nationally.
It has found weak or absent management and supervision of crime-recording, under recording of crime, serious sexual offences not being recorded, and some offenders having being dealt with out of court when their offending history could not justify it.
South Yorkshire is one of 13 forces inspected.
During a sample of incidents reviewed by HMIC in South Yorkshire, inspectors found 118 should have been recorded as crime when only 89 were.
Tom Winsor, HM Chief Inspector of Constabulary,, said: “The accuracy and integrity of police-recorded crime data are vital to public trust in the police.
“The consequences of under-recording of crime are serious, and may mean victims and the community are failed because crimes are not investigated, the levels of crime will be wrongly under-stated, and police chiefs will lack the information they need to make sound decisions on the deployment of their resources.”