Only 3.5 per cent of rape allegations in Sussex result in a conviction, according to the latest Government figures.

There were 257 reported rapes last year. Of those, 47 led to a court case with nine people found guilty.

But experts said it was not unusual for conviction rates to be so low.

Rape Crisis Federation figures show there were 8,049 rapes reported nationally last year and fewer than ten per cent resulted in prosecution.

Jane White, from Peacehaven, sits on an advisory panel at Scotland Yard which deals with the police handling of rape cases.

She also advised the BBC on how to handle the storyline when Little Mo was raped by her bullying husband Trevor in EastEnders. She said there were many reasons for the low rates.

She said: "The police may decide after investigating there is not enough evidence to prosecute. Or the Crown Prosecution Service may not proceed because it doesn't think it will secure a conviction.

"The police are trying to do something about conviction rates but once it goes to the CPS it is out of their hands.

"They are also looking at the best ways of dealing with women who have been raped to ensure they receive better treatment.

"The number of women who phone organisations like Rape Crisis for support don't call the police so many cases go unreported.

"Many cases are women raped by their husband or someone they know and are either too frightened or unwilling to give evidence against them. These are just some of the problems."

Karen Jewitt, manager of the Rape and Sexual Abuse Support Centre in Croydon, south London, said: "Last year we dealt with more than 6,000 calls.

"That figure will increase this year because we are now dealing with cases from Brighton and Hove as a result of the Rape Crisis centre there closing in December."

She said it was not unusual for conviction rates to be so low.

She said: "There are many obstacles before a victim gives evidence against an attacker in court. Many victims know the person who has raped them and very few attacks are what are known as stranger rapes."

Fiona Grant, of Sussex Police's Anti-Victimisation Unit, said: "There has been a big increase in the number of domestic violence incidents being reported since the unit was set up.

"A number of those would include allegations of rape, which would be investigated by us. Rapes by strangers are investigated by other detectives."

"Victims receive help throughout the process."

The Government has announced plans to reform the law on rape.

The legal definition of consent is likely to be changed so the prosecution only has to prove a victim has not given their "voluntary and genuine agreement".

It will cite examples of where consent is not given, including when a person was asleep or could not resist because of alcohol or drugs.

Moves to make it easier for victims to give evidence via video link or from behind a screen will be introduced this summer.