The CCRC referred the case to the Court of Appeal at the end of November 1997, and the conviction was quashed eight months later on the grounds that the terms of a note in Mrs James' handwriting, discovered by the Trial and Error team more than two years after her death, were consistent with an intention to commit suicide. The case was aptly summed up by Coleman Treacy, QC, who represented Ryan James: "The prosecution say this was murder made to look like suicide. We say it was most likely suicide made to look like murder."

A vet has had his life sentence for the murder of his wife quashed at the Court of Appeal.

Ryan James showed no emotion as the three judges said that his conviction was unsound. They allowed him to go free after three-and-a-half years in prison for allegedly spiking his wife's orange juice with horse tranquiliser.

His murder conviction "must be regarded as unsafe" they said, and added they would announce their reasons in due course.

Mr James said outside the court: "I'm glad that this ordeal is over. I have always maintained I did not kill my wife."

The reversal follows the discovery of a hand-written note, first detailed on the BBC's Trial and Error, suggesting his wife Sandra intended to kill herself.

The note was discovered in an old copy of the Veterinary Record by James' partner Catherine Crooks.

It said: "Ryan, I leave you absolutely nothing but this note - if you find it in time. Sam." Sam was Mrs James' pet name.

Counsel for James, Mr Coleman Treacy, QC, had urged the court to overturn the murder conviction as "unsafe". Mr Treacy said: "The overwhelming balance of the evidence, as it is now, points away from Mr James being responsible for his wife's death and points to her as the person responsible for it."

He said the note "showed suicidal intent".

The court was also told there was evidence that Mrs James was likely to have been suffering from a depressive illness at the time of her death. There had been previous episodes in the 70s when she was prescribed anti-depressants.

James, 43, had always claimed his 39-year-old wife committed suicide. The vet was a partner in a practice at Burton upon Trent where the initial prosecution said he obtained everything he needed to kill his wife.

James had been said to have poisoned her with Immobilon, a powerful horse sedative, so he could collect her £180,000 life insurance and start a new life with his Mrs Crooks.

She moved into James' home after his wife's death.

After the guilty verdict at Stafford Crown Court in May 1995, Mr Justice Anthony Hidden told James he was "the most evil, selfish and criminally callous man" he had ever sentenced. James's initial appeal was rejected in March 1996.

James won the right to a new appeal after the Criminal Cases Review Commission found there was a "real possibility" his conviction would not be upheld.

The case was heard by Lord Justice Evans, sitting with Mr Justice Sedley and Mr Justice Hooper in London and had been expected to last three days.

Cryptic message pointed to woman's plot to frame her husband as her killer, writes Richard Duce

A single cryptic line written by Sandra James in the week before she died could have come straight from the plot of a Ruth Rendell novel.

Left bitter and depressed by the breakdown of her marriage and her husband's affair, she decided to stage her own "murder" and leave him to take the blame. But, before overdosing on a drug used to knock out horses, the vet's wife wrote out one line in blue ink and hid it in one of his professional journals.

On a sheet torn from a notebook, she wrote: "Ryan, I leave you absolutely nothing but this note - if you find it in time, Sam."

The note was not discovered for more than two years after the death of Mrs James, 39, whose pet name was Sam. By then Ryan James, now 43, had been jailed for life for murder and described by the trial judge, Mr Justice Hidden, as "the most evil, selfish and criminally callous man" he had sentenced.

Mr James married his lover, Catherine Crooks, in Gartree prison and it was she who found the crucial note when she was sorting through her new husband's belongings.

Mr James had already lost an appeal against his conviction and a recommended 20-year sentence imposed at Stafford Crown Court in May 1995. The note provided critical evidence that his second wife had committed suicide.

Mrs James had been portrayed as the innocent victim of a murder plot that would have allowed her husband to start a new life with Ms Crooks with the proceeds of a a £180,000 life insurance policy for his wife. Yesterday, after his conviction was quashed by the Court of Appeal, it became clear that the father of three had himself been the victim of an intricate plot.

Mrs James learnt of her husband's affair with Ms Crooks, whom he met at a school meeting, in September 1993. The lovers left their spouses to live together but the cost of running two homes drove the vet back to his wife.

The affair led Mrs James to change her will, stipulating that in the event of her death it must be read in her husband's presence. "To my husband I leave absolutely nothing. I loved you and lost you. I will never forget," she instructed in the document, dated September 13, 1993.

At the turn of the year Mrs James, who had a 20-year history of depression, was taking the drug phenobarbitone which friends noticed left her drowsy. She obtained Immobilon, a drug used to put large animals to sleep, and its antidote. It is not known whether it was taken from her husband's veterinary practice in Burton upon Trent, or from his car. The court was told yesterday that she probably experimented by injecting the drug into her foot and immediately taking the antidote. The puncture wounds on her foot were not satisfactorily explained at Mr James's trial although it was accepted that they were not linked to her death.

On the night of January 13, 1994, Mrs James mixed a fatal dose of Immobilon with orange juice and drained the glass while her husband was visiting his mistress. Up to a week before, she had put the note in a copy of The Veterinary Record.

Mr Ryan returned home to discover his wife dead. He was charged with murder two weeks later.

At his trial he said that his wife had made her suicide look like murder. The jury chose to believe Peter Joyce, QC, for the prosecution, who said: "It is the case of the eternal triangle. Mr James could not afford to live with his mistress, he had everything to gain by his wife's death and nothing to gain from divorce. She was the one standing in the way of his living with his mistress. There were also substantial debts of £143,000 which were wiped out by her death."

Ms Crooks's belief in her lover's innocence never wavered and she became his third wife during a 15-minute ceremony in prison on September 24, 1995. On March 30, 1996, she made the discovery that yesterday allowed them to begin married life proper.