THE murder conviction of James Hanratty, who was hanged 40 years ago protesting his innocence, was upheld yesterday by the Court of Appeal, which ruled that DNA evidence established his guilt ''beyond doubt''.

Lord Woolf, the Lord Chief Justice, sitting with Lord Justice Mantell and Mr Justice Leveson, announced their decision in the posthumous appeal to a packed court in London.

In one of the most celebrated cases in British history, Hanratty, 25, was hanged on April 4, 1962, for the notorious A6 murder in Bedfordshire, in which scientist Michael Gregsten, 36, was shot dead. Mr Gregsten's 22-year-old mistress, Valerie Storie, was raped and shot. She survived but was left paralysed from the waist down.

Giving the lengthy ruling of the court, Lord Woolf said: ''In our judgment . . . the DNA evidence establishes beyond doubt that James Hanratty was the murderer.'' He said the DNA evidence ''made what was a strong case even stronger''. Hanratty's case - one of the country's longest-running alleged miscarriages of justice - was referred back to the Appeal Court by the Criminal Cases Review Commission (CCRC).

Since his execution at Bedford prison, Hanratty's family and supporters have fought to prove he was not a killer.

During the appeal Michael Mansfield, QC, for Hanratty, argued that his trial was ''fatally flawed'' with ''extensive and inexcusable'' non-disclosure of significant material in the case.

In contesting the appeal, the Crown sought to rely on findings of Hanratty's DNA on two exhibits, a fragment of Miss Storie's knickers and a handkerchief wrapped around the murder weapon.

Hanratty's body was exhumed last year from its burial plot at Carpenders Park, near Watford, and tests confirmed that it was his DNA on the exhibits.

One of the central issues before the judges was the possibility that his DNA was present on two exhibits because of ''contamination'' prior to the start of scientific tests in 1995. But the Court of Appeal rejected the possibility of contamination.

Lord Woolf said that at Hanratty's trial the defence described the case as ''sagging with coincidences''. He added: ''Just let us consider some of the more striking coincidences in the light of the DNA evidence if James Hanratty was not guilty.

''He was wrongly identified by three witnesses at identification parades; first as the person at the scene of the crime and secondly (by two witnesses) driving a vehicle close to where the vehicle in which the murder was committed was found.

''He had the same identifying manner of speech as the killer; he stayed in a room the night before the crime from which bullets that had been fired from the murder weapon were recovered; the murder weapon was recovered from a place on a bus which he regarded as a hiding place and the bus followed a route he could well have used.''

Lord Woolf said: ''The number of alleged coincidences means that they are not coincidences but overwhelming proof of the safety of the conviction from an evidential perspective.''

Lord Woolf, before completing the three-hour long judgment, said it was right that the court should mention the Hanratty family and their supporters.

He said: ''Throughout the appeal we have observed that they have attended in significant numbers and followed the proceedings behaving impeccably.''

Later one of Hanratty's brothers Michael, 63, said he was ''appalled'' by the ruling and vowed that the family would fight on to clear the hanged man. ''We have to get legal advice. We will fight on to the House of Lords, and then on to the European Court if we have to. For 40 years there has been a cover-up.''

Lord Woolf certified the case raised a point of general public importance but refused the family leave to go to the House of Lords, although they can now petition the Lords direct.

Detective Inspector Stewart Trail, who led the Metropolitan Police team which reviewed the original evidence in preparation for the appeal, paid tribute to Valerie Storie. He said: ''I know that today's result will mean a great deal to her.''