More than nine out of ten crimes in Sussex go unpunished by the courts, government figures revealed today.

Sussex Police's 8.5 per cent conviction rate is the second worst in England and Wales, ahead of only the Metropolitan Police.

Besides the Met, Sussex is the only force not to reach double figures and lies well below the national average of 13.4 per cent.

It has been disclosed just 11,696 convictions resulted from 136,920 crimes in Sussex in the year to March 2001.

Sussex Police spokesman Chris Oswick admitted detection rates dipped in that period from 24.9 per cent to 23 per cent but rose to 25.5 per cent the following year.

He said: "The point we would make is overall crime was down in the last year and we were one of only five forces where detection improved.

"The figures expose a technical difference between detections and convictions in court.

"Some detections are dealt with as cautions, some as crimes taken into consideration at court and some where the Crown Prosecution Service decides it is not in the public interest for the prosecution to take place."

Alison Saunders, Sussex's chief crown prosecutor, said: "We are determined to reduce the current size of the justice gap.

"One of the main causes is witnesses who do not turn up in court. We are looking at ways of encouraging them to support a prosecution.

"We are also taking a more robust approach to domestic violence even if the victim is reluctant to proceed.

"Criminal justice agencies in Sussex have shown we can improve the system by working together.

"Our record in getting persistent young offenders through the courts shows what can be done."

The CPS is working with police to ensure cases are not discontinued unnecessarily.

Police minister John Denham said the Home Office was seeking to rebalance the judicial system in favour of the victim.

The new Criminal Justice Bill will end the double jeopardy rule forbidding someone being tried twice for the same offence. It will be reversed for murder, rape and armed robbery and will be applied retrospectively.

In some cases, juries will be told whether a defendant or witness has a relevant previous conviction and some hearsay evidence will be allowed in court.

In a separate move, ministers also aim to improve the conviction rate for rape.

Men accused of date rape will no longer be able to claim as a defence they genuinely believed their partner wanted to have sex.