Mr Lynn, 50, is due to stand trial at Dublin Circuit Criminal Court next year on 21 counts of stealing the money from seven financial institutions.

In two of the sample charges, Mr Lynn is accused of stealing €4.1 million from Irish Nationwide on 4 April 2007 and €3.6 million from Ulster Bank on 20 October 2006.

He left Ireland in 2007 but was extradited from Brazil last year, after spending four-and-a-half years on remand at the Cotel prison, in northwestern Brazil, as he fought his extradition back to Ireland.

Ahead of his extradition, Brazilian authorities sought assurances from Ireland that any time Mr Lynn spent in prison awaiting extradition would be deducted from any potential prison sentence here, and that he would not serve more than 30 years in prison here, if found guilty. The assurances were required as part of the Brazilian extradition process.

His lawyers challenged those assurances, arguing that they couldn’t be given due to the separation of powers. Counsel for Mr Lynn, Padraig Dwyer SC, told the Court of Appeal that a favourable outcome of the case might strengthen Mr Lynn’s attempts to prohibit his upcoming criminal trial.

However, dismissing the case on Friday, Mr Justice George Birmingham, president of the Court of Appeal, said it seemed “a matter of absolute certainty” that account will taken of the time Mr Lynn has spent in custody, if found guilty.

Furthermore, he said there was “no possibility whatsoever” of Mr Lynn being required to spend more than 30 years in prison, if found guilty.

He said Brazilian law viewed such a sentence as analogous to cruel and inhuman punishment. However, he said, there was no recorded case of anybody being sentenced to more than 30 years in prison in Ireland.

In the “most unlikely event” that were to happen, he said Mr Lynn could appeal. There was also remission to consider and the fact the Executive are entitled to release a prisoner at any stage, the judge said.

Mr Justice Birmingham said he rejected Mr Lynn’s arguments. Mr Justice John Edwards and Ms Justice Isobel Kennedy “fully agreed” with his decision.

A recommendation for free legal aid was granted.

Ruaidhrí Giblin, Ireland International News Agency Ltd.