Director of Public Prosecutions Barbara Mills QC and High Court judge John Chadwick QC could be called to provide affidavits and oral evidence to the Court of Appeal concerning their role in advising the Serious Fraud Office in the first Guinness trial.
As senior members of the prosecution team, they are understood to have advised the SFO on the non-disclosure of the findings of a Licensed Dealers Tribunal in the City during the first trial, which the original four defendants believe could help overturn their convictions and result in millions of pounds in compensation.
The team subsequently disclosed the tribunal's report in the second Guinness trial against Lord Spens.
The City tribunal had found no fault with the type of share-dealing techniques that were used in the Guinness share-support operation.
However, some white collar crime lawyers believe the tribunal report - into dealings by broker THW - is unlikely to help the four defendants.
Lawyers, who were close to the Guinness case, say the appeal court will have to ascertain:
whether the tribunal report was unused material gathered by the prosecution which should have been disclosed to the defence;
that it actually constitutes evidence, rather than simply a tribunal finding;
how relevant the report is to the case, in terms of whether it covers matters not already argued before a court;
whether it shows that share-supporting deals were in fact commonplace.