The Court of Criminal Appeal has set aside a six-year sentence imposed on a Dublin businessman for failing to pay €1.6m in garlic import duty.
However, Paul Begley from Rathcoole in Dublin remains in custody until next month, pending further submissions on an alternative sentence.
The appeal court ruled the sentence imposed last March was not proportionate and that the trial judge had erred in principle by failing to take into account mitigating factors.
The 47-year-old was given the longest sentence ever handed down for this type of offence.
At an appeal hearing last month, Begley's lawyers said the trial judge ignored his guilty plea and offer to repay the tax.
Begley's tax evasion scheme was uncovered in 2007.
He had been importing garlic from China for a number of years and made huge savings on import tax by having it labelled as apples.
This afternoon the three-judge appeal court said the trial judge failed to give any explanation for imposing the maximum sentence of five years on one count.
Delivering the judgment, Justice Liam McKechnie said there was an error of principle by the trial judge in excluding mitigating factors.
The court said Begley's level of cooperation with investigators was, if not unprecedented, then at the very higher end of such processes.
"In effect, the book of evidence was entirely supplied by the defendant", the judgment said.
Begley's guilty plea should merit serious consideration along with his offer of restitution, which was a material factor for mitigation.
His genuine remorse, an impressive list of testimonials and the fact that he had no previous convictions, was totally rehabilitated and unlikely to reoffend were all matters that should have been considered.
It was not open to the trial judge to impose the sentence which he did and the mitigating factors were either entirely overlooked or not properly valued.
The court will hear submissions on an alternative sentence on 4 February.
Begley's original trial heard that tax on imported garlic was inexplicably high at more than 200%, while for other fruit and vegetables it was only 9%.
But Judge Martin Nolan said the tax was not a matter for individuals to decide. He said it was a grave and huge tax evasion scheme and jailed him for six years.
During his appeal, senior counsel Patrick Gageby said Begley had cooperated fully with the investigation, had handed over all his files and had, in effect, been the architect of the prosecution case against him.
He said the trial judge had ignored Begley's guilty plea, had ignored the fact that he had paid the tax and had handed down a maximum sentence, which should normally be reserved for the worst cases and the worst circumstances.
Opposing the appeal, counsel for the DPP said the amount involved (€1.6m) was at the highest end of the scale.
The offence was carried out for no reason other than greed and it gave Begley a competitive advantage over other businesses.