The Court of Appeal expressed its frustration yesterday over a technicality that forced it to send a young woman convicted of a crime she did not commit back to prison for another week - in order to free her. Yan Suk-yin, now 25, was jailed for 11 years in March 2001 after a Court of First Instance jury found her guilty of trafficking in 113 grams of the designer drug 'Ice', or crystal methamphetamine. Yesterday, however, the Court of Appeal ruled Yan should never have been sent to jail on that charge and swapped it for one of possession. Yan had been in jail for 3.5 years - the equivalent of five years under custodial calculations and more than three times the sentence she would have received on a possession conviction. As a result, the court yesterday said she should have been able to walk free from the dock. Unfortunately, under the Dangerous Drugs Ordinance, any person convicted of possession must be assessed for a Drug Addiction Training Centre report before sentencing. This meant Yan must be returned to jail until the report is completed. Mr Justice Frank Stock said: 'I am a little astonished that under the circumstances, we have to do this and we can't impose a custodial sentence [for the lesser charge] unless we do this step . . . I don't think we have any choice.' He ordered the report, which can take up to three weeks to prepare, be ready for a sitting on March 20. The court heard from Yan's counsel, Paul Loughran, that his client's parents had committed suicide in January last year.