The Criminal Cases Review Commission (CCRC) sent a 75-page document to Stone's lawyers setting out its reasons for the refusal to grant a new appeal in January 2009.
They could then either be referred to the police to investigate or to the CCRC, which currently receives up to 1, 000 referrals per year to review convictions and sentences.
The court then instructed the CCRC to look at "particular points" as part of the appeal process and it sent its report to the Court of Appeal last October for it to consider.
The CCRC said it looked at more than 50 individual points raised by Stone's lawyers in application and carried out a "substantial amount" of fresh forensic testing on material from the crime scene.
On his third attempt, the case was sent to the Court of Appeal after new information came to light regarding the credibility of the main police witness, the Criminal Cases Review Commission (CCRC) said.