Prominent republican Thomas ‘Slab’ Murphy was found guilty of evading tax his brother had already paid, his lawyers have submitted to the Court of Appeal.

Murphy is serving an 18-month sentence for tax evasion following a Criminal Assets Bureau investigation.

Murphy’s barrister John Kearney said the Special Criminal Court's ten-page ruling was inadequately brief for such a document heavy case and that the court had erred in narrowing the case down to a number of core issues

Murphy has appealed his conviction on 48 grounds in seven key areas including the question of independence, the admission of a statement under provisions known as 'section 16’ and alleged defects in the verdict.

The hearing, which is being held before three judges, is expected to last three days