THE Burnley sister of former paratrooper Christopher Alder said today her fight for justice over his death was a step closer.

Janet Alder, who has campaigned for justice for her brother since he died in a Humberside police station six years ago, said she welcomed the decision that the family can challenge for a public inquiry handed down by High Court judge Mr Justice Munby.

Christopher's son Leon Wilson went to the High Court to argue for a public inquiry into the circumstances surrounding the death.

Mr Justice Munby ruled yesterday that a full High Court hearing to challenge Home Secretary David Blunkett's refusal to hold a public inquiry should be allowed to go ahead.

Janet said the court heard earlier this month the investigations into the death, including the inquest and involvement from the Police Complaints Authority (PCA), had been inadequate.

She said the barrister, Hugh Southey, said that under the Human Rights Act there had to be "adequate investigation" into deaths in custody.

Mum-of-two Janet said: "The High Court judgement is excellent news. The public inquiry is the only way to find out the whole truth surrounding Christopher's death. We will keep fighting until we have got the truth."

Father-of-two, Christopher, 37, died face down with his trousers around his ankles after he was arrested for a breach of the peace outside a Hull nightclub.

An inquest concluded that he was unlawfully killed. Five police officers - Sergeant John Dunn, 40, and PCs Neil Blakey, 42; Mark Ellerington, 37; Nigel Dawson, 41, and Matthew Barr, 38 - were cleared of neglect of duty at an independent hearing following Christopher's death at Queen's Gardens police station, Hull, on April 1, 1998.

In the criminal trial that followed, all five officers were cleared of manslaughter and misconduct in a public office.