Serial rapists may be escaping justice because of failures by police and prosecutors, a report has claimed.

One in eight reported rapes are written off as if no crime ever took place, chances to identify links between offences are being missed, and forces are failing to check the criminal records of foreign nationals, the review found.

The critical inspection report called for police and prosecutors to make changes that "can make a real difference in catching and convicting repeat and serial rapists".

On average, reported rapes were four times as likely as reported incidents of grievous bodily harm with intent (GBH) to end with officers deeming that no crime had been committed, figures showed.

Almost 12% of reported rapes in 2010 were "no crimed", compared with just 3% of GBH cases, the joint report by Her Majesty's Inspectorates of Constabulary (HMIC) and the Crown Prosecution Service (HMCPSI) showed.

"While we acknowledge that no two crime types are the same, we think the comparison is worth making, in order to help illustrate what we believe is a considerable problem," the inspectors said.

The so-called "no crime" figures for rape cases rose to 30% in Kent and fell to 2.4% in Gloucestershire, the review found.

Analysis of a small sample of at least 100 such "no crimes" from each force also showed the decision was wrong in more than one in 10 (11%) cases.

Rapists could also be convicted more quickly and successfully if police and prosecutors made better use of available intelligence, the review found.

Profiles used by forces to draw together information on rapes in their area were only up-to-date and in line with national standards in three of the 43 forces in England and Wales.

And the potential use of partial DNA samples in eliminating suspects, directing investigations or identifying possible links between cases was also being overlooked, the review said.

The inspectors also criticised the "bureaucratic" Serious Crime Analysis Section (Scas), a national police unit set up to provide intelligence on serious sexual offences, for being too concerned with assessing force compliance with the process for supplying it with information.

A change of approach "could increase the numbers of serious sexual offences that are analysed in 'real-time' investigations", the inspectors said.

They also found that rape investigations were being hindered because police and prosecutors were failing to check the criminal records of foreign nationals.

Interpol record checks in relation to rapes "were not regularly conducted", even though they could help to identify a pattern of offending or make links between offences in the UK and those which took place abroad, the review said.

The inspectors backed a Home Office review which found what while around 35,000 EU nationals were convicted in the UK in 2010, only 7,590 checks on foreign nationals' records were ordered.

"Police do not utilise the range of facilities available for checking international notice information as fully as possible," they said.

"This is partly because of a perception in forces (which we found to be unfounded) that the process for getting to this information was complicated and unwieldy.

"Increased awareness of the facilities to access intelligence on foreign nationals committing rape offences in domestic jurisdiction could be instrumental in identifying serial and repeat offenders earlier."

Police chiefs should support "an urgent and all-force review of the awareness and use of existing processes for identifying foreign intelligence to ensure that risks to the public are mitigated", the inspectors added.

Dru Sharpling, an inspector of constabulary, said: "The safe conviction of those guilty of rape is powerful protection for victims and society at large.

"Whilst the service for victims is getting better, there is absolutely no room for complacency and good intelligence, the right investigative approach and targeting resources effectively are key to preventing rape and catching perpetrators."

Michael Fuller, chief inspector of HMCPSI, added that while progress has been made, "closer working between prosecutors and investigators should be the standard in all rape investigations".

The Association of Chief Police Officers (Acpo) said rape was "one of the most difficult offences police and prosecutors deal with".
Chief Constable Dave Whatton, the Acpo lead for rape and serious sexual offences, said: "This review rightly acknowledges improvements in recent years to the way victims of rape are treated.

"Improvements in specialist training of officers, introduction of early evidence kits, better access to sexual assault referral centres and significantly improved crime recording practices have assisted the policing response.

"But we know that there is no room for complacency.

"As with any review, we need to ensure that the best practices are shared amongst all to ensure consistency in our approach to supporting victims and investigating and prosecuting rape."