900,000 crimes, including rape, not pursued by police in 2013

3.7 million Crimes recorded in England and Wales last year (Getty Images)

Nearly a million criminal offences including rape have gone unrecorded by police in a single year, according to a damning report that could see the 20-year decline in recorded crime reversed when accurate statistics are calculated.

Inspectors said they suspected “discreditable and unethical” behaviour by some officers and said they had discovered 14 reported rapes that were wrongly categorised in a study of 13 of the 43 police forces in England and Wales.

They included the case of a 13-year-old boy with autism who complained of an attack by a 15-year-old friend but the case was written off as “sexual experimentation” because of the negative effect it might have on the victim.

In another case, an officer failed to record a case of rape because it involved too much work and it was believed would not lead to a prosecution, according to a report by the Inspectorate of Constabulary (HMIC). In other cases, police gave cautions to people whose past records meant they should have been prosecuted.

The study follows the intervention by a whistleblower and a series of scandals over recorded police crime rates that have shown dramatic reductions over the past 20 years. PC James Patrick told a parliamentary committee last year that massaging figures was an “ingrained part of policing culture”. A subsequent report by MPs suggested that a “target junkie” culture was in part to blame for tampering with crime statistics.

The inspectorate suggested there could be a nationwide under-recording of 20 per cent of crimes – adding more than 900,000 crimes to the 3.7 million recorded last year in England and Wales.

Theresa May, the Home Secretary, said: “HMIC’s interim report exposes unacceptable failings by the police. It is quite possible, once HMIC has completed its work on recorded crime statistics and made recommendations on how the police need to improve, that we will see an increase in recorded crime.”

The inspectorate said that it could not establish in every case the motivation for mis-recording or failure to record a crime. But it said: “In the light of what we have so far found… it is difficult to conclude that none of these failures was the result of discreditable or unethical behaviour.”

Adam Pemberton, assistant Chief Executive at Victim Support, said: “This is about much more than inaccurate statistics or poor number-crunching – each mistake represents a victim losing their chance to get justice and to access support services. It is completely unacceptable that victims of any crimes – let alone serious sexual offences such as rape – should have their complaints go unrecorded or downgraded because of police incompetence or even laziness.”

The report follows a series of scandals that has resulted in the Statistics Authority stripping police statistics of its official stamp of approval.

Four Scotland Yard officers were put under investigation in March after a criminal claimed that he was persuaded to accept responsibility for 500 burglaries. It followed a criminal inquiry in Kent, after inspectors raised concerns over the manipulation of crime statistics to meet targets.

The inspectorate later found that one in 10 crimes had been under-recorded, but the results of its latest report suggest inaccuracies of a much higher level. The report comes after the Government has claimed successes for a decline in recorded crime despite budget cuts.

Paul Ford, of the Police Federation which represents officers up to the rank of chief inspector, said: “Frontline colleagues, supervisors and leaders are struggling to cope. Too often, officers are overloaded with cases and this affects the service they are able to offer.”