The Crown Prosecution Service has been left with a large bill after flying two witnesses from China to give evidence in a case which collapsed.

Andy Wang and his girlfriend, Yan Yan Zhao, both 22, were beaten with golf clubs as they crossed playing fields at Falmer School on August 30 in what police described as a racist attack.

Mr Wang was left with a head wound needing nine stitches and Miss Zhao suffered bruising to her legs.

The couple, studying English at Brighton University, were walking to their host home in Moulsecoomb, Brighton.

Nine youths were arrested and five of them, aged between 13 and 16, were charged with a public order offence of threatening or using violence.

The five youths, who cannot be named because of their age, denied the charges.

During a six day trial at the Brighton youth court Mr Wang and Miss Zhao were requested to give evidence. They were flown back to Brighton and put up in a city hotel.

They gave their evidence through an interpreter who was hired for the case.

Although they gave their evidence early in the trial, they had to remain in case either the prosecution or defence required them to answer further questions.

But on day seven, District Judge Ann Arnold dismissed all charges against the five youths.

She told the court she was unable to convict the youths of the attack because there were uncertainties surrounding their identification.

She said: "What I can't be sure of is the identity, considering the number of youths involved."

The Crown Prosecution could not tell The Argus how much the case had cost taxpayers.

Running a magistrates trial for one day, with one solicitor costs about £550. The trial ran for more than six days with one prosecution solicitor.

A return air fair from China to Britain with the Chinese national airline would cost around £517 each plus airport taxes.

The couple had their living costs paid for but that figure has not been disclosed.

A spokesman for the Crown Prosecution Service said it had to pay for any witnesses to appear at any trial.