Ministers have long been concerned about low rape conviction rates
Every police force should set up a specialist squad to investigate rape allegations, a senior officer says.
John Yates, who speaks on the issue for the Association of Chief Police Officers, argues such teams would help raise standards of victim care.
They would also help improve conviction rates as rape inquiries are demanding and require specialist skills, he told a London conference on the issue.
About 6% of reported rapes in England and Wales result in a conviction.
Five per cent of women have experienced rape but only 15% of victims report their attack to the police, according to the British Crime Survey.
Of reported rape cases, 70% do not even make it to court, according to the survey.
Metropolitan Police Assistant Commissioner John Yates, who speaks for Acpo in England, Wales and Northern Ireland, called for a consistent approach to investigating rape, at a conference of senior officers, organised by the Home Office, in London.
Some uniformed officers have been trained to deal with sexual assaults, but investigations are often carried out by detectives drawn from a general pool.
Mr Yates wants every force to have its own rape investigation unit, along the lines of child protection and murder teams.
He argues more expertise in the early stages of an investigation would improve the quality of evidence gathered and prevent rapes being wrongly classified as "no crime".
Why police drop cases:
Insufficient evidence 21%
Victim withdrawal 17%
Victim declined to complete initial process 17%
Offender not identified 13%
False allegation 12%
No evidence of assault 5%
No prospect of conviction 2%
Not in public interest 1%
Other/ unknown 12%
From 2001/ 02 research at two specialist rape referral centres, a support service, and three comparison areas with no specialist provision
He said: "In recent years we have made significant advances in the way we approach investigation of this difficult offence, but despite that, delivery remains inconsistent and there is much more to do."
Mr Yates said rape was a difficult crime to investigate given that most cases involved people who knew each other, where consent was the primary issue.
"But the fact that it's difficult means we need to up our game and redouble our efforts to ensure victims can have confidence in the way they are approached by those working in the criminal justice system," he said.
"We are determined to ensure the best possible standards are reached and applied uniformly across the country."
Home Office Minister Vernon Coaker said the government was determined to improve rape conviction rates and acknowledged the crime remained under-reported.
He highlighted progress, including the introduction of specially trained officers and prosecutors and better guidance for police.
He added: "Every force has a responsibility to ensure that every single officer who comes into contact with a rape victim is supportive and believes the victim.
Figures for England and Wales only. Changes in the way crime statistics were collected from April 2002 may have contributed to increased reported rape figure.
"It may only take the raising of an eyebrow to cause her to lose courage."
Women's equality group, the Fawcett Society, welcomed the government's drive to improve police responses to victims of rape.
But policy officer Sarah Campbell said: "The fact that only 5.7% of reported rapes lead to a conviction is a national scandal.
"The government needs to drive cultural change within the criminal justice system, to ensure that rape is given a high priority by every police force in the country and to invest in a national network of rape crisis centres."
The group released a map this week highlighting how in some areas, women who report they have been raped are almost five times less likely to see their attacker convicted than in other areas.
It says the conviction rate has got worse in 18 out of 43 police areas since it last looked at the figures in detail in 2004.
The map showed that fewer than one in 30 women who reported a rape in Leicestershire saw a conviction, while in Cleveland the figure was far higher, at about one in seven.
The Survivors Trust, an umbrella organisation for services working with survivors of rape, sexual violence and childhood sexual abuse, welcomed the idea of specialist squads.
But chief executive Fay Maxted said: "You can't separate out a highly trained, specialist squad when the first person that a victim contacts doesn't know what to do. The training needs to be for everyone."
A spokeswoman for the campaigning group Women Against Rape said: "Over three decades we have seen the police and the government unleash an avalanche of new policies, procedures, specialists, experts, initiatives, conferences and press releases, while conviction rates have fallen or stuck at such an appalling level that women call us wondering what is the point of reporting rape."
Mr Yates' call came as one force, West Yorkshire, officially unveiled a pilot specialist Rape Investigation Unit.
It is headed by Det Insp Dick Nuttall, who said: "We now have a dedicated team of specialist investigators who can focus their growing expertise on investigating reports of rape, gathering the strongest possible evidence from the outset and giving continuity to the investigation."
The unit, based in Bradford and Wakefield, comprises a team of 35 officers specially trained to investigate rape.