Ryan James spoke of his relief outside the court

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.

Ryan James thanked the prosecution for accepting new evidence

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 handwritten note, first detailed on the BBC's Rough Justice, 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.

Conviction 'unsafe'

The BBC correspondent Stephen Cape says the prosecution agreed the note was genuine

Counsel for James, Mr Colman 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 protested innocence

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.