One in five crimes reported to 13 forces, including Hertfordshire, went unrecorded due to failures from the police, a report has revealed.
The interim report by Her Majesty's Inspectorate of Constabulary (HMIC) into several police forces, including Hertfordshire, found tens of thousands of offences could be going unrecorded by police.
Hertfordshire Police and Crime Commissioner David Lloyd said in a written statement that he is concerned the report has identified failings in recording procedures but he has received "personal assurance" from the HMIC that there is no evidence of deliberate manipulation of figures in Hertfordshire, or a lack of integrity amongst officers and staff.
The police force in Hertfordshire was inspected in March and the report revealed 181 crimes were reported but only 130 were recorded.
The report explained that occasionally recorded crimes are found not to have occurred. Where there is additional information to show this is the case, the record of the crime can be reclassified and is then recorded as a non-crime. In Hertfordshire, the number of incorrect no-crime decisions was 4 compared with 71 that were correct.
The inspection looked at 13 forces and the report found 14 rapes were among offences not recorded by officers, including an allegation made by a 13-year-old autistic boy written off as "sexual experimentation''.
The police watchdog also found some offenders were issued with out-of-court disposals when they should have been prosecuted.
Home Secretary Theresa May said the report exposed "unacceptable failings by the police'' and warned that once HMIC concludes its work in October, official figures may show a spike in police recorded crime.
Councillor Lloyd said: "Accurate recording of crime is important to inform operational policing and I need to make sure that Hertfordshire Constabulary is getting it right.
"I had already asked the chief to review the accuracy of recording and some key changes have since been made.
"I have now also asked him to implement the recommendations in the report and I will be holding him closely to account for doing so.
"We should not lose sight of the fact that Hertfordshire is a safe place and our police force is doing an excellent job in policing the county.
"While there have been some shortcomings in meeting the Home Office recording standards, the criteria and interpretation applied by the constabulary have been consistent over time and so I am completely confident that the overall picture, showing a big fall in crime over the last few years, is an accurate one."