The Special Criminal Court has been accused of disregarding the defence's pieces of the jigsaw in Thomas 'Slab' Murphy's tax evasion trial.
The prominent Republican, of Ballybinaby, Hackballscross, Co. Louth was jailed in February for not filing tax returns between 1996 and 2004.
Thomas 'Slab' Murphy was convicted last December and jailed for 18 months.
He claimed he was not a chargeable person, that his brother Patrick ran the family farm and that he was the victim of an identity theft.
In a 10-page judgement, the non-jury Special Criminal Court said it was "satisfied beyond reasonable doubt" that he was, and that he had received Government grants and income from the sale of cattle.
Today was the second day of his appeal against conviction and sentence.
His barrister John Kearney QC has strongly criticised the prosecution and the way the three judges arrived at their decision.
Among his 48 grounds of appeal is an accusation that they relied on unreliable evidence and took only seven pieces of the prosecution's evidence and totally disregarded the defence's evidence.
"All of the pieces of the jigsaw must fit together," he said, "and the alternative picture must also be considered."
The appeal will enter its third day tomorrow.