Juveniles who are guilty of murders can legitimately be sentenced to jail terms of about 30 years, the Court of Appeal ruled yesterday.
The court rejected an appeal by a killer who was 15 at the time of his crime to have his 30-year sentence reduced.
Lee Kar-yeung, now 17, helped three older youths strangle a loanshark and saw his body into pieces which have never been found.
Jerome Matthews, for Lee, said the teenager might spend longer behind bars than if he had been given a life sentence.
Adult life sentences are reviewed every few years, meaning that the amount of time 'lifers' serve can vary greatly.
Mr Matthews argued that laws introduced in 1997 allowing courts to sentence murderers under 18 to definite terms were intended to lead to them receiving shorter sentences.