Victims of stalking are let down by a justice system that fails to recognise the extent of the abuse, both emotional and physical, according to a report published today.

Only one in 50 stalking cases reported to police results in a suspect being sent to prison, the study found, and many of those put behind bars receive only short jail terms during which little or nothing is done to tackle their obsessive behaviour.

Harry Fletcher, assistant general secretary of the National Association of Probation Officers (Napo), said stalking laws need to be reformed and for earlier intervention by the police and courts to prevent harassment escalating into more serious crimes.

?It is abundantly clear that if the criminal justice system does not intervene early to prevent stalking behaviour, then that behaviour escalates to violence and even murder,?he said.

The British Crime Survey, which is based on interviews with more than 40,000 people, estimates that about one in five women and one in ten men age 16 and over have been victims of stalking.

In 2009, police recorded 53,000 cases of stalking which resulted in 6,581 people being found guilty in court, according to the report by Napo.

It is not known what happened to the remaining 46,000 reported cases but it said further action was not taken in the majority of them.

Mr Fletcher said the number of people receiving a jail term of more than twelve months for the more serious crime of harrassment which puts someone in fear of violence was an average of 20 for each of the last five years.

The Napo study of 80 offenders convicted of stalking behaviour in 2010-11 found that court reports focus on the immediate issues and fail to take into account previous history or harassment.

It said this meant sentences failed to reflect the seriousness of the crime, its long term nature and the abuse endured by victims who are mostly women. The report added that short sentences mean there is little time to tackle the reasons behind the harassment.

?As a consequence of this women who are being stalked are placed at grave risk,? Mr Fletcher said.

Earlier this year Assistant Chief Constable Garry Shewan of the Association of Chief Police Officers, said: ?It is important to remember that stalking isn?t a ?one-off? crime. It?s a series of incidents which when taken in isolation can appear trivial but when put together they become far more sinister.

?The challenge for the police service and other agencies is to protect victims by recognising the danger signs, by effective use of legislation and by effective and co-ordinated investigation.?

In England and Wales, an all-party group of MPs and peers is currently investigating the issues around stalking.

The group is looking to revise and strengthen the Protection from Harassment Act 1997, the law currently used to prosecute stalkers in England and Wales and is due to report in early next year.