Sinn Féin president Gerry Adams has been criticised for claiming that former IRA chief of staff Thomas 'Slab' Murphy was treated unfairly by the authorities in the Republic.
Mr Adams spoke out after 66-year-old Murphy, from Hackballscross in Co Louth, was convicted of tax evasion at the Special Criminal Court in Dublin.
The Sinn Féin leader said all citizens had the right to be judged by a jury of their peers.
"It is extraordinary a case involving a failure to complete tax returns is heard before a non-jury court," he said.
"Tom Murphy's rights have been denied to him."
The three judges in the trail heard how Murphy had made a number of major financial deals involving cattle and land, while also receiving farm subsidies. However, he failed to submit tax returns for nine years.
The prosecution was brought after an investigation by the Republic's Criminal Assets Bureau (CAB).
Murphy, whose farm that straddles the border, had denied the charges.
He was remanded on continuing bail ahead of sentencing in February.
Mr Adams said in a statement there could be "no equivocation" that "everyone has a duty to pay the taxes for which they are liable".
He said "many prominent public figures accused of tax irregularities, including TDs ... have not been treated in the same fashion as Mr Murphy.
"Neither have they been labelled as criminals by those media outlets currently writing lurid headlines about Mr Murphy."
The Sinn Féin leader said he considered Murphy to be a "good republican".
But Fianna Fáil leader Micheál Martin described Mr Adams’s remarks as "absolutely extraordinary" and said they underlined his assertion that Sinn Féin was "not fit for government"
"This response is completely consistent with how Sinn Féin leadership has behaved in a string of cases in recent times – they are more interested in protecting their own than respecting and enforcing the rule of law," Mr Martin said.
He said the Louth TD's comments highlight Slab Murphy's continued importance the "Sinn Féin project".
"It is incredible that Adams would concentrate on the unfairness of this case when it took the Criminal Assets Bureau to carry out this investigation in the first place – CAB does not normally investigate routine non-payment of tax," he said.
"Decent republicans are tax compliant."
Mr Martin accused his Sinn Féin counterpart of "not facing up to the paramilitary criminality".
"His comments, when read alongside the recent independent report into paramilitary activity in the north, provide a chilling insight into how Mr Adams and his organisation do their business," he said.
