Luke Mitchell was convicted of murder in 2003
A man who claimed to have evidence which could clear Luke Mitchell of his girlfriend's murder hoped to sell his story, appeal court judges have heard.
Scott Forbes came forward 18 months after Mitchell had been given a life sentence for the murder of Jodi Jones, pointing to a possible "suspect".
Mitchell's defence team want the Court of Criminal Appeal in Edinburgh to hear more about Mr Forbes's claims.
Mitchell is serving a minimum of 20 years for murdering Jodi in June 2003.
The court heard that drug addict Mark Kane was supposed to have been near the woods where Jodi, 14, was murdered.
He was also said to have been acting strangely in the days following the killing and to have sustained unexplained injuries to his face.
Defence counsel, Donald Findlay QC, said Mr Kane, "ticked all the same boxes" as Mitchell.
Mr Findlay said Mr Forbes had given a sworn statement last month and his claims were still being investigated.
But John Beckett QC, for the Crown, revealed that police investigations cast doubt on what Mr Forbes had told solicitors and a BBC Frontline Scotland programme in May last year.
Mr Forbes had alleged that Mr Kane, a student at Newbattle Abbey College at the time of Jodi's murder, had written an essay on "killing a girl in the woods".
The body of Jodi Jones was found on a footpath near her home
He also claimed that a teacher at the college could confirm this.
Mr Beckett said: "When this came to light the Crown had police take a statement from the lecturer which confirmed Kane wrote no such essay at all."
Mr Beckett also said Mr Forbes had told Mr Kane to co-operate "and we will get £50,000 from the newspapers".
In December, appeal judges were told there was circumstantial evidence pointing to two possible "suspects".
One was Mr Kane and the other was a local man in his 20s, James Falconer.
Mr Findlay told judges he was dropping any further claims about Mr Falconer, who has vigorously protested his innocence since he was first named.
The lawyer wants judges to consider the arguments he has been making over six days that Luke Mitchell did not get a fair trial.
If they do not quash the conviction on the grounds he has already put forward, he wants them to fix another date in about 10 weeks time, to hear the new claims about Mr Kane.
Mitchell, 19, is attempting to overturn his conviction for the murder of his girlfriend when they were both 14-year-old pupils at St David's High School in Dalkeith, Midlothian.
Her naked and mutilated body was found in woods beside Roan's Dyke path, Dalkeith.
The path connects Jodi's home in the Easthouses part of the town with Mitchell's home in the Newbattle area.
The appeal hearing before Scotland's top judge, Lord Hamilton - sitting with Lords Osborne and Kingarth - is set to continue all this week, at least.
Afterwards they are expected to issue a decision in writing at a later date which could free Mitchell, send him back to jail, or order a re-trial.
Meanwhile, the Crown promised to give the court 20 reasons why the jury could return a guilty verdict.
Mr Beckett said: "The Crown support the conviction and in my submission none of the grounds of appeal has been made out individually and there has been no miscarriage of justice.
"There was no direct evidence against him and the case was entirely circumstantial in nature.
"I contend there is both sufficient evidence and a rational basis for the conviction."
Mr Beckett argued that the jury believed witness Andrina Bryson, who said she saw Mitchell and a girl who could have been Jodi near the time the murder is thought to have occurred.
To do so they rejected Mitchell's alibi, claiming he was at home at the time, he said.