Jones has always maintained that on the day Harry and Megan Tooze were found shot dead at their farmhouse in mid-Glamorgan he was in the Kent town of Orpington where he lived with the couple's daughter, Cheryl.
Miss Tooze, who lived with Jones for eight years, has run a fierce campaign since her lover's imprisonment to free him and track down the killers of her parents. Last week her battle was boosted by the trial judge Mr Justice Rougier, who said in a letter to the Home Secretary that the guilty verdict had come as a surprise to him.
Now Jones's supporters believe that evidence has come to light which could well help secure his release from prison.
After his conviction, one of his legal team, Leyla Attfield, went to Kent with a Welsh rugby team anorak that Jones had been wearing on the day of the killings in a bid to track down witnesses to support his alibi.
She said: "I saw certain people in Orpington and I do not want to say too much about it at this stage, but it does look very important."
Jonathan Jones was charged with murder and jailed for life five weeks ago. He said he had been in Orpington on the day of the murders and had only driven to the Toozes' farmhouse that night because Cheryl was worried when she could get no answer to her telephone calls.
Miss Tooze has offered a £25,000 reward for information that will help track down the killer of her parents.Reuse content